path: root/contrib/ntp/NEWS

--
NTP 4.2.8p10 (Harlan Stenn <stenn@ntp.org>, 2017/03/21) 

Focus: Security, Bug fixes, enhancements.

Severity: MEDIUM

This release fixes 5 medium-, 6 low-, and 4 informational-severity
vulnerabilities, and provides 15 other non-security fixes and improvements:

* NTP-01-016 NTP: Denial of Service via Malformed Config (Medium)
   Date Resolved: 21 Mar 2017
   References: Sec 3389 / CVE-2017-6464 / VU#325339
   Affects: All versions of NTP-4, up to but not including ntp-4.2.8p10, and
	ntp-4.3.0 up to, but not including ntp-4.3.94.
   CVSS2: MED 4.6 (AV:N/AC:H/Au:M/C:N/I:N/A:C)
   CVSS3: MED 4.2 CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
   Summary:
	A vulnerability found in the NTP server makes it possible for an
	authenticated remote user to crash ntpd via a malformed mode
	configuration directive.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page or
	    the NTP Public Services Project Download Page
	Properly monitor your ntpd instances, and auto-restart
	    ntpd (without -g) if it stops running. 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-014 NTP: Buffer Overflow in DPTS Clock (Low)
    Date Resolved: 21 Mar 2017
    References: Sec 3388 / CVE-2017-6462 / VU#325339
    Affects: All versions of NTP, up to but not including ntp-4.2.8p10, and ntp-4.3.0 up to, but not including ntp-4.3.94.
    CVSS2: Low 1.0 (AV:L/AC:H/Au:S/C:N/I:N/A:P)
    CVSS3: Low 1.6 CVSS:3.0/AV:P/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L
    Summary:
	There is a potential for a buffer overflow in the legacy Datum
	Programmable Time Server refclock driver.  Here the packets are
	processed from the /dev/datum device and handled in
	datum_pts_receive().  Since an attacker would be required to
	somehow control a malicious /dev/datum device, this does not
	appear to be a practical attack and renders this issue "Low" in
	terms of severity.
   Mitigation:
	If you have a Datum reference clock installed and think somebody
	    may maliciously change the device, upgrade to 4.2.8p10, or
	    later, from the NTP Project Download Page or the NTP Public
	    Services Project Download Page
	Properly monitor your ntpd instances, and auto-restart
	    ntpd (without -g) if it stops running. 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-012 NTP: Authenticated DoS via Malicious Config Option (Medium)
   Date Resolved: 21 Mar 2017
   References: Sec 3387 / CVE-2017-6463 / VU#325339
   Affects: All versions of ntp, up to but not including ntp-4.2.8p10, and
	ntp-4.3.0 up to, but not including ntp-4.3.94.
   CVSS2: MED 4.6 (AV:N/AC:H/Au:M/C:N/I:N/A:C)
   CVSS3: MED 4.2 CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
   Summary:
	A vulnerability found in the NTP server allows an authenticated
	remote attacker to crash the daemon by sending an invalid setting
	via the :config directive.  The unpeer option expects a number or
	an address as an argument.  In case the value is "0", a
	segmentation fault occurs.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page 
	Properly monitor your ntpd instances, and auto-restart
	    ntpd (without -g) if it stops running. 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-011 NTP: ntpq_stripquotes() returns incorrect value (Informational)
   Date Resolved: 21 Mar 2017
   References: Sec 3386
   Affects: All versions of NTP, up to but not including ntp-4.2.8p10, and
	ntp-4.3.0 up to, but not including ntp-4.3.94.
   CVSS2: None 0.0 (AV:N/AC:H/Au:N/C:N/I:N/A:N)
   CVSS3: None 0.0 CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:N
   Summary:
	The NTP Mode 6 monitoring and control client, ntpq, uses the
	function ntpq_stripquotes() to remove quotes and escape characters
	from a given string.  According to the documentation, the function
	is supposed to return the number of copied bytes but due to
	incorrect pointer usage this value is always zero.  Although the
	return value of this function is never used in the code, this
	flaw could lead to a vulnerability in the future.  Since relying
	on wrong return values when performing memory operations is a
	dangerous practice, it is recommended to return the correct value
	in accordance with the documentation pertinent to the code.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your ntpd instances, and auto-restart
	    ntpd (without -g) if it stops running. 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-010 NTP: ereallocarray()/eallocarray() underused (Info)
   Date Resolved: 21 Mar 2017
   References: Sec 3385
   Affects: All versions of NTP, up to but not including ntp-4.2.8p10, and
	ntp-4.3.0 up to, but not including ntp-4.3.94.
   Summary:
	NTP makes use of several wrappers around the standard heap memory
	allocation functions that are provided by libc.  This is mainly
	done to introduce additional safety checks concentrated on
	several goals.  First, they seek to ensure that memory is not
	accidentally freed, secondly they verify that a correct amount
	is always allocated and, thirdly, that allocation failures are
	correctly handled.  There is an additional implementation for
	scenarios where memory for a specific amount of items of the
	same size needs to be allocated.  The handling can be found in
	the oreallocarray() function for which a further number-of-elements
	parameter needs to be provided.  Although no considerable threat
	was identified as tied to a lack of use of this function, it is
	recommended to correctly apply oreallocarray() as a preferred
	option across all of the locations where it is possible.
   Mitigation:
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-009 NTP: Privileged execution of User Library code (WINDOWS
	PPSAPI ONLY) (Low)
   Date Resolved: 21 Mar 2017
   References: Sec 3384 / CVE-2017-6455 / VU#325339
   Affects: All Windows versions of ntp-4 that use the PPSAPI, up to but
	not including ntp-4.2.8p10, and ntp-4.3.0 up to, but not
	including ntp-4.3.94.
   CVSS2: MED 3.8 (AV:L/AC:H/Au:S/C:N/I:N/A:C)
   CVSS3: MED 4.0 CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
   Summary:
	The Windows NT port has the added capability to preload DLLs
	defined in the inherited global local environment variable
	PPSAPI_DLLS.  The code contained within those libraries is then
	called from the NTPD service, usually running with elevated
	privileges. Depending on how securely the machine is setup and
	configured, if ntpd is configured to use the PPSAPI under Windows
	this can easily lead to a code injection.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page 
   Credit:
   This weakness was discovered by Cure53. 

* NTP-01-008 NTP: Stack Buffer Overflow from Command Line (WINDOWS
	installer ONLY) (Low)
   Date Resolved: 21 Mar 2017
   References: Sec 3383 / CVE-2017-6452 / VU#325339
   Affects: WINDOWS installer ONLY: All versions of the ntp-4 Windows
	installer, up to but not including ntp-4.2.8p10, and ntp-4.3.0 up
	to, but not including ntp-4.3.94.
   CVSS2: Low 1.0 (AV:L/AC:H/Au:S/C:N/I:N/A:P)
   CVSS3: Low 1.8 CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L
   Summary:
	The Windows installer for NTP calls strcat(), blindly appending
	the string passed to the stack buffer in the addSourceToRegistry()
	function.  The stack buffer is 70 bytes smaller than the buffer
	in the calling main() function.  Together with the initially
	copied Registry path, the combination causes a stack buffer
	overflow and effectively overwrites the stack frame.  The
	passed application path is actually limited to 256 bytes by the
	operating system, but this is not sufficient to assure that the
	affected stack buffer is consistently protected against
	overflowing at all times.
   Mitigation:
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	or the NTP Public Services Project Download Page 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-007 NTP: Data Structure terminated insufficiently (WINDOWS
	installer ONLY) (Low)
   Date Resolved: 21 Mar 2017
   References: Sec 3382 / CVE-2017-6459 / VU#325339
   Affects: WINDOWS installer ONLY: All ntp-4 versions of the Windows
	installer, up to but not including ntp-4.2.8p10, and ntp-4.3.0
	up to, but not including ntp-4.3.94.
   CVSS2: Low 1.0 (AV:L/AC:H/Au:S/C:N/I:N/A:P)
   CVSS3: Low 1.8 CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L
   Summary:
	The Windows installer for NTP calls strcpy() with an argument
	that specifically contains multiple null bytes.  strcpy() only
	copies a single terminating null character into the target
	buffer instead of copying the required double null bytes in the
	addKeysToRegistry() function.  As a consequence, a garbage
	registry entry can be created.  The additional arsize parameter
	is erroneously set to contain two null bytes and the following
	call to RegSetValueEx() claims to be passing in a multi-string
	value, though this may not be true.
   Mitigation:
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-006 NTP: Copious amounts of Unused Code (Informational)
   References: Sec 3381
   Summary:
	The report says: Statically included external projects
	potentially introduce several problems and the issue of having
	extensive amounts of code that is "dead" in the resulting binary
	must clearly be pointed out.  The unnecessary unused code may or
	may not contain bugs and, quite possibly, might be leveraged for
	code-gadget-based branch-flow redirection exploits.  Analogically,
	having source trees statically included as well means a failure
	in taking advantage of the free feature for periodical updates.
	This solution is offered by the system's Package Manager. The
	three libraries identified are libisc, libevent, and libopts.
   Resolution:
	For libisc, we already only use a portion of the original library.
	We've found and fixed bugs in the original implementation (and
	offered the patches to ISC), and plan to see what has changed
	since we last upgraded the code.  libisc is generally not
	installed, and when it it we usually only see the static libisc.a
	file installed.  Until we know for sure that the bugs we've found
	and fixed are fixed upstream, we're better off with the copy we
	are using.

        Version 1 of libevent was the only production version available
	until recently, and we've been requiring version 2 for a long time.
	But if the build system has at least version 2 of libevent
	installed, we'll use the version that is installed on the system.
	Otherwise, we provide a copy of libevent that we know works.

        libopts is provided by GNU AutoGen, and that library and package
	undergoes frequent API version updates.  The version of autogen
	used to generate the tables for the code must match the API
	version in libopts.  AutoGen can be ... difficult to build and
	install, and very few developers really need it.  So we have it
	on our build and development machines, and we provide the
	specific version of the libopts code in the distribution to make
	sure that the proper API version of libopts is available.

        As for the point about there being code in these libraries that
	NTP doesn't use, OK.  But other packages used these libraries as
	well, and it is reasonable to assume that other people are paying
	attention to security and code quality issues for the overall
	libraries.  It takes significant resources to analyze and
	customize these libraries to only include what we need, and to
	date we believe the cost of this effort does not justify the benefit. 
   Credit:
	This issue was discovered by Cure53. 

* NTP-01-005 NTP: Off-by-one in Oncore GPS Receiver (Low)
   Date Resolved: 21 Mar 2017
   References: Sec 3380
   Affects: All versions of NTP, up to but not including ntp-4.2.8p10, and
   	ntp-4.3.0 up to, but not including ntp-4.3.94.
   CVSS2: None 0.0 (AV:L/AC:H/Au:N/C:N/I:N/A:N)
   CVSS3: None 0.0 CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:N
   Summary:
	There is a fencepost error in a "recovery branch" of the code for
	the Oncore GPS receiver if the communication link to the ONCORE
	is weak / distorted and the decoding doesn't work.
   Mitigation:
        Upgrade to 4.2.8p10, or later, from the NTP Project Download Page or
	    the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart
	    ntpd (without -g) if it stops running. 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-004 NTP: Potential Overflows in ctl_put() functions (Medium)
   Date Resolved: 21 Mar 2017
   References: Sec 3379 / CVE-2017-6458 / VU#325339
   Affects: All versions of NTP, up to but not including ntp-4.2.8p10, and
	ntp-4.3.0 up to, but not including ntp-4.3.94.
   CVSS2: MED 4.6 (AV:N/AC:H/Au:M/C:N/I:N/A:C)
   CVSS3: MED 4.2 CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
   Summary:
	ntpd makes use of different wrappers around ctl_putdata() to
	create name/value ntpq (mode 6) response strings.  For example,
	ctl_putstr() is usually used to send string data (variable names
	or string data).  The formatting code was missing a length check
	for variable names.  If somebody explicitly created any unusually
	long variable names in ntpd (longer than 200-512 bytes, depending
	on the type of variable), then if any of these variables are
	added to the response list it would overflow a buffer.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	If you don't want to upgrade, then don't setvar variable names
	    longer than 200-512 bytes in your ntp.conf file.
	Properly monitor your ntpd instances, and auto-restart
	    ntpd (without -g) if it stops running. 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-003 NTP: Improper use of snprintf() in mx4200_send() (Low)
   Date Resolved: 21 Mar 2017
   References: Sec 3378 / CVE-2017-6451 / VU#325339
   Affects: All versions of NTP, up to but not including ntp-4.2.8p10, and
	ntp-4.3.0 up to, but not including ntp-4.3.94.
   CVSS2: LOW 0.8 (AV:L/AC:H/Au:M/C:N/I:N/A:P)
   CVSS3: LOW 1.8 CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:L/A:N
   Summary:
	The legacy MX4200 refclock is only built if is specifically
	enabled, and furthermore additional code changes are required to
	compile and use it.  But it uses the libc functions snprintf()
	and vsnprintf() incorrectly, which can lead to an out-of-bounds
	memory write due to an improper handling of the return value of
	snprintf()/vsnprintf().  Since the return value is used as an
	iterator and it can be larger than the buffer's size, it is
	possible for the iterator to point somewhere outside of the
	allocated buffer space.  This results in an out-of-bound memory
	write.  This behavior can be leveraged to overwrite a saved
	instruction pointer on the stack and gain control over the
	execution flow.  During testing it was not possible to identify
	any malicious usage for this vulnerability.  Specifically, no
	way for an attacker to exploit this vulnerability was ultimately
	unveiled.  However, it has the potential to be exploited, so the
	code should be fixed.
   Mitigation, if you have a Magnavox MX4200 refclock:
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page.
	Properly monitor your ntpd instances, and auto-restart
	    ntpd (without -g) if it stops running. 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-002 NTP: Buffer Overflow in ntpq when fetching reslist from a
	malicious ntpd (Medium)
   Date Resolved: 21 Mar 2017
   References: Sec 3377 / CVE-2017-6460 / VU#325339
   Affects: All versions of ntpq, up to but not including ntp-4.2.8p10, and
	ntp-4.3.0 up to, but not including ntp-4.3.94.
   CVSS2: MED 4.9 (AV:N/AC:H/Au:S/C:N/I:N/A:C)
   CVSS3: MED 4.2 CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
   Summary:
	A stack buffer overflow in ntpq can be triggered by a malicious
	ntpd server when ntpq requests the restriction list from the server.
	This is due to a missing length check in the reslist() function.
	It occurs whenever the function parses the server's response and
	encounters a flagstr variable of an excessive length.  The string
	will be copied into a fixed-size buffer, leading to an overflow on
	the function's stack-frame.  Note well that this problem requires
	a malicious server, and affects ntpq, not ntpd.
   Mitigation:
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	If you can't upgrade your version of ntpq then if you want to know
	    the reslist of an instance of ntpd that you do not control,
	    know that if the target ntpd is malicious that it can send back
	    a response that intends to crash your ntpq process. 
   Credit:
	This weakness was discovered by Cure53. 

* NTP-01-001 NTP: Makefile does not enforce Security Flags (Informational)
   Date Resolved: 21 Mar 2017
   References: Sec 3376
   Affects: All versions of NTP, up to but not including ntp-4.2.8p10, and
	ntp-4.3.0 up to, but not including ntp-4.3.94.
   CVSS2: N/A
   CVSS3: N/A
   Summary:
	The build process for NTP has not, by default, provided compile
	or link flags to offer "hardened" security options.  Package
	maintainers have always been able to provide hardening security
	flags for their builds.  As of ntp-4.2.8p10, the NTP build
	system has a way to provide OS-specific hardening flags.  Please
	note that this is still not a really great solution because it
	is specific to NTP builds.  It's inefficient to have every
	package supply, track and maintain this information for every
	target build.  It would be much better if there was a common way
	for OSes to provide this information in a way that arbitrary
	packages could benefit from it.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your ntpd instances, and auto-restart
	    ntpd (without -g) if it stops running. 
   Credit:
	This weakness was reported by Cure53. 

* 0rigin DoS (Medium)
   Date Resolved: 21 Mar 2017
   References: Sec 3361 / CVE-2016-9042 / VU#325339
   Affects: ntp-4.2.8p9 (21 Nov 2016), up to but not including ntp-4.2.8p10
   CVSS2: MED 4.9 (AV:N/AC:H/Au:N/C:N/I:N/A:C) (worst case)
   CVSS3: MED 4.4 CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H (worst case)
   Summary:
	An exploitable denial of service vulnerability exists in the
	origin timestamp check functionality of ntpd 4.2.8p9.  A specially
	crafted unauthenticated network packet can be used to reset the
	expected origin timestamp for target peers.  Legitimate replies
	from targeted peers will fail the origin timestamp check (TEST2)
	causing the reply to be dropped and creating a denial of service
	condition.  This vulnerability can only be exploited if the
	attacker can spoof all of the servers.
   Mitigation:
	Implement BCP-38.
	Configure enough servers/peers that an attacker cannot target
	    all of your time sources.
	Upgrade to 4.2.8p10, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your ntpd instances, and auto-restart
	    ntpd (without -g) if it stops running. 
   Credit:
	This weakness was discovered by Matthew Van Gundy of Cisco. 

Other fixes:

* [Bug 3393] clang scan-build findings <perlinger@ntp.org>
* [Bug 3363] Support for openssl-1.1.0 without compatibility modes
  - rework of patch set from <ntp.org@eroen.eu>. <perlinger@ntp.org>
* [Bug 3356] Bugfix 3072 breaks multicastclient <perlinger@ntp.org>
* [Bug 3216] libntp audio ioctl() args incorrectly cast to int
  on 4.4BSD-Lite derived platforms <perlinger@ntp.org>
  - original patch by Majdi S. Abbas
* [Bug 3215] 'make distcheck' fails with new BK repo format <perlinger@ntp.org>
* [Bug 3173] forking async worker: interrupted pipe I/O <perlinger@ntp.org>
  - initial patch by Christos Zoulas
* [Bug 3139] (...) time_pps_create: Exec format error <perlinger@ntp.org>
  - move loader API from 'inline' to proper source
  - augment pathless dlls with absolute path to NTPD
  - use 'msyslog()' instead of 'printf() 'for reporting trouble
* [Bug 3107] Incorrect Logic for Peer Event Limiting <perlinger@ntp.org>
  - applied patch by Matthew Van Gundy
* [Bug 3065] Quiet warnings on NetBSD <perlinger@ntp.org>
  - applied some of the patches provided by Havard. Not all of them
    still match the current code base, and I did not touch libopt.
* [Bug 3062] Change the process name of forked DNS worker <perlinger@ntp.org>
  - applied patch by Reinhard Max. See bugzilla for limitations.
* [Bug 2923] Trap Configuration Fail <perlinger@ntp.org>
  - fixed dependency inversion from [Bug 2837]
* [Bug 2896] Nothing happens if minsane < maxclock < minclock
  - produce ERROR log message about dysfunctional daemon. <perlinger@ntp.org>
* [Bug 2851] allow -4/-6 on restrict line with mask <perlinger@ntp.org>
  - applied patch by Miroslav Lichvar for ntp4.2.6 compat
* [Bug 2645] out-of-bound pointers in ctl_putsys and decode_bitflags
  - Fixed these and some more locations of this pattern.
    Probably din't get them all, though. <perlinger@ntp.org>
* Update copyright year.

--
(4.2.8p9-win) 2017/02/01 Released by Harlan Stenn <stenn@ntp.org>

* [Bug 3144] NTP does not build without openSSL. <perlinger@ntp.org>
  - added missed changeset for automatic openssl lib detection
  - fixed some minor warning issues
* [Bug 3095]  More compatibility with openssl 1.1. <perlinger@ntp.org>
* configure.ac cleanup.  stenn@ntp.org
* openssl configure cleanup.  stenn@ntp.org

--
NTP 4.2.8p9 (Harlan Stenn <stenn@ntp.org>, 2016/11/21) 

Focus: Security, Bug fixes, enhancements.

Severity: HIGH

In addition to bug fixes and enhancements, this release fixes the
following 1 high- (Windows only), 2 medium-, 2 medium-/low, and
5 low-severity vulnerabilities, and provides 28 other non-security
fixes and improvements:

* Trap crash
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3119 / CVE-2016-9311 / VU#633847
   Affects: ntp-4.0.90 (21 July 1999), possibly earlier, up to but not
   	including 4.2.8p9, and ntp-4.3.0 up to but not including ntp-4.3.94.
   CVSS2: MED 4.9 (AV:N/AC:H/Au:N/C:N/I:N/A:C)
   CVSS3: MED 4.4 CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
   Summary: 
	ntpd does not enable trap service by default. If trap service
	has been explicitly enabled, an attacker can send a specially
	crafted packet to cause a null pointer dereference that will
	crash ntpd, resulting in a denial of service. 
   Mitigation:
        Implement BCP-38.
	Use "restrict default noquery ..." in your ntp.conf file. Only
	    allow mode 6 queries from trusted networks and hosts. 
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Matthew Van Gundy of Cisco.

* Mode 6 information disclosure and DDoS vector
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3118 / CVE-2016-9310 / VU#633847
   Affects: ntp-4.0.90 (21 July 1999), possibly earlier, up to but not
	including 4.2.8p9, and ntp-4.3.0 up to but not including ntp-4.3.94.
   CVSS2: MED 6.4 (AV:A/AC:L/Au:N/C:N/I:N/A:P)
   CVSS3: MED 6.5 CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
   Summary: 
	An exploitable configuration modification vulnerability exists
	in the control mode (mode 6) functionality of ntpd. If, against
	long-standing BCP recommendations, "restrict default noquery ..."
	is not specified, a specially crafted control mode packet can set
	ntpd traps, providing information disclosure and DDoS
	amplification, and unset ntpd traps, disabling legitimate
	monitoring. A remote, unauthenticated, network attacker can
	trigger this vulnerability. 
   Mitigation:
        Implement BCP-38.
	Use "restrict default noquery ..." in your ntp.conf file.
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Matthew Van Gundy of Cisco.

* Broadcast Mode Replay Prevention DoS
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3114 / CVE-2016-7427 / VU#633847
   Affects: ntp-4.2.8p6, up to but not including ntp-4.2.8p9, and 
	ntp-4.3.90 up to, but not including ntp-4.3.94.
   CVSS2: LOW 3.3 (AV:A/AC:L/Au:N/C:N/I:N/A:P)
   CVSS3: MED 4.3 CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
   Summary: 
	The broadcast mode of NTP is expected to only be used in a
	trusted network. If the broadcast network is accessible to an
	attacker, a potentially exploitable denial of service
	vulnerability in ntpd's broadcast mode replay prevention
	functionality can be abused. An attacker with access to the NTP
	broadcast domain can periodically inject specially crafted
	broadcast mode NTP packets into the broadcast domain which,
	while being logged by ntpd, can cause ntpd to reject broadcast
	mode packets from legitimate NTP broadcast servers. 
   Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Matthew Van Gundy of Cisco.

* Broadcast Mode Poll Interval Enforcement DoS
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3113 / CVE-2016-7428 / VU#633847
   Affects: ntp-4.2.8p6, up to but not including ntp-4.2.8p9, and
	ntp-4.3.90 up to, but not including ntp-4.3.94
   CVSS2: LOW 3.3 (AV:A/AC:L/Au:N/C:N/I:N/A:P)
   CVSS3: MED 4.3 CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
   Summary: 
	The broadcast mode of NTP is expected to only be used in a
	trusted network. If the broadcast network is accessible to an
	attacker, a potentially exploitable denial of service
	vulnerability in ntpd's broadcast mode poll interval enforcement
	functionality can be abused. To limit abuse, ntpd restricts the
	rate at which each broadcast association will process incoming
	packets. ntpd will reject broadcast mode packets that arrive
	before the poll interval specified in the preceding broadcast
	packet expires. An attacker with access to the NTP broadcast
	domain can send specially crafted broadcast mode NTP packets to
	the broadcast domain which, while being logged by ntpd, will
	cause ntpd to reject broadcast mode packets from legitimate NTP
	broadcast servers. 
   Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Matthew Van Gundy of Cisco.

* Windows: ntpd DoS by oversized UDP packet
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3110 / CVE-2016-9312 / VU#633847
   Affects Windows only: ntp-4.?.?, up to but not including ntp-4.2.8p9,
	and ntp-4.3.0 up to, but not including ntp-4.3.94. 
   CVSS2: HIGH 7.8 (AV:N/AC:L/Au:N/C:N/I:N/A:C)
   CVSS3: HIGH 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
   Summary: 
	If a vulnerable instance of ntpd on Windows receives a crafted
	malicious packet that is "too big", ntpd will stop working. 
   Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Robert Pajak of ABB.

* 0rigin (zero origin) issues
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3102 / CVE-2016-7431 / VU#633847
   Affects: ntp-4.2.8p8, and ntp-4.3.93.
   CVSS2: MED 5.0 (AV:N/AC:L/Au:N/C:N/I:P/A:N)
   CVSS3: MED 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
   Summary: 
	Zero Origin timestamp problems were fixed by Bug 2945 in
	ntp-4.2.8p6. However, subsequent timestamp validation checks
	introduced a regression in the handling of some Zero origin
	timestamp checks.
   Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Sharon Goldberg and Aanchal
	Malhotra of Boston University.

* read_mru_list() does inadequate incoming packet checks
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3082 / CVE-2016-7434 / VU#633847
   Affects: ntp-4.2.7p22, up to but not including ntp-4.2.8p9, and
	ntp-4.3.0 up to, but not including ntp-4.3.94.
   CVSS2: LOW 3.8 (AV:L/AC:H/Au:S/C:N/I:N/A:C)
   CVSS3: LOW 3.8 CVSS:3.0/AV:P/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
   Summary: 
	If ntpd is configured to allow mrulist query requests from a
	server that sends a crafted malicious packet, ntpd will crash
	on receipt of that crafted malicious mrulist query packet.
   Mitigation:
	Only allow mrulist query packets from trusted hosts.
        Implement BCP-38.
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Magnus Stubman.

* Attack on interface selection
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3072 / CVE-2016-7429 / VU#633847
   Affects: ntp-4.2.7p385, up to but not including ntp-4.2.8p9, and
	ntp-4.3.0 up to, but not including ntp-4.3.94
   CVSS2: LOW 1.0 (AV:L/AC:H/Au:S/C:N/I:N/A:P)
   CVSS3: LOW 1.6 CVSS:3.0/AV:P/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L
   Summary: 
	When ntpd receives a server response on a socket that corresponds
	to a different interface than was used for the request, the peer
	structure is updated to use the interface for new requests. If
	ntpd is running on a host with multiple interfaces in separate
	networks and the operating system doesn't check source address in
	received packets (e.g. rp_filter on Linux is set to 0), an
	attacker that knows the address of the source can send a packet
	with spoofed source address which will cause ntpd to select wrong
	interface for the source and prevent it from sending new requests
	until the list of interfaces is refreshed, which happens on
	routing changes or every 5 minutes by default. If the attack is
	repeated often enough (once per second), ntpd will not be able to
	synchronize with the source.
   Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	If you are going to configure your OS to disable source address
	    checks, also configure your firewall configuration to control
	    what interfaces can receive packets from what networks.
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Miroslav Lichvar of Red Hat.

* Client rate limiting and server responses
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3071 / CVE-2016-7426 / VU#633847
   Affects: ntp-4.2.5p203, up to but not including ntp-4.2.8p9, and
	ntp-4.3.0 up to, but not including ntp-4.3.94
   CVSS2: LOW 1.0 (AV:L/AC:H/Au:S/C:N/I:N/A:P)
   CVSS3: LOW 1.6 CVSS:3.0/AV:P/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L
   Summary: 
	When ntpd is configured with rate limiting for all associations
	(restrict default limited in ntp.conf), the limits are applied
	also to responses received from its configured sources. An
	attacker who knows the sources (e.g., from an IPv4 refid in
	server response) and knows the system is (mis)configured in this
	way can periodically send packets with spoofed source address to
	keep the rate limiting activated and prevent ntpd from accepting
	valid responses from its sources. 

	While this blanket rate limiting can be useful to prevent
	brute-force attacks on the origin timestamp, it allows this DoS
	attack. Similarly, it allows the attacker to prevent mobilization
	of ephemeral associations.  
   Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Miroslav Lichvar of Red Hat.

* Fix for bug 2085 broke initial sync calculations 
   Date Resolved: 21 November 2016; Dev (4.3.94) 21 November 2016
   References: Sec 3067 / CVE-2016-7433 / VU#633847
   Affects: ntp-4.2.7p385, up to but not including ntp-4.2.8p9, and
	ntp-4.3.0 up to, but not including ntp-4.3.94. But the
	root-distance calculation in general is incorrect in all versions
	of ntp-4 until this release. 
   CVSS2: LOW 1.2 (AV:L/AC:H/Au:N/C:N/I:N/A:P)
   CVSS3: LOW 1.6 CVSS:3.0/AV:P/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L
   Summary: 
	Bug 2085 described a condition where the root delay was included
	twice, causing the jitter value to be higher than expected. Due
	to a misinterpretation of a small-print variable in The Book, the
	fix for this problem was incorrect, resulting in a root distance
	that did not include the peer dispersion. The calculations and
	formulae have been reviewed and reconciled, and the code has been
	updated accordingly. 
   Mitigation:
        Upgrade to 4.2.8p9, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered independently by Brian Utterback of
	Oracle, and Sharon Goldberg and Aanchal Malhotra of Boston University. 

Other fixes:

* [Bug 3142] bug in netmask prefix length detection <perlinger@ntp.org>
* [Bug 3138] gpsdjson refclock should honor fudgetime1. stenn@ntp.org
* [Bug 3129] Unknown hosts can put resolver thread into a hard loop
  - moved retry decision where it belongs. <perlinger@ntp.org>
* [Bug 3125] NTPD doesn't fully start when ntp.conf entries are out of order
  using the loopback-ppsapi-provider.dll <perlinger@ntp.org>
* [Bug 3116] unit tests for NTP time stamp expansion. <perlinger@ntp.org>
* [Bug 3100] ntpq can't retrieve daemon_version <perlinger@ntp.org>
  - fixed extended sysvar lookup (bug introduced with bug 3008 fix)
* [Bug 3095] Compatibility with openssl 1.1 <perlinger@ntp.org>
  - applied patches by Kurt Roeckx <kurt@roeckx.be> to source
  - added shim layer for SSL API calls with issues (both directions)
* [Bug 3089] Serial Parser does not work anymore for hopfser like device
  - simplified / refactored hex-decoding in driver. <perlinger@ntp.org>
* [Bug 3084] update-leap mis-parses the leapfile name.  HStenn.
* [Bug 3068] Linker warnings when building on Solaris. perlinger@ntp.org
  - applied patch thanks to Andrew Stormont <andyjstormont@gmail.com>
* [Bug 3067] Root distance calculation needs improvement.  HStenn
* [Bug 3066] NMEA clock ignores pps. perlinger@ntp.org
  - PPS-HACK works again.
* [Bug 3059] Potential buffer overrun from oversized hash <perlinger@ntp.org>
  - applied patch by Brian Utterback <brian.utterback@oracle.com>
* [Bug 3053] ntp_loopfilter.c frequency calc precedence error.  Sarah White.
* [Bug 3050] Fix for bug #2960 causes [...] spurious error message.
  <perlinger@ntp.org>
  - patches by Reinhard Max <max@suse.com> and Havard Eidnes <he@uninett.no>
* [Bug 3047] Fix refclock_jjy C-DEX JST2000. abe@ntp.org
  - Patch provided by Kuramatsu.
* [Bug 3021] unity_fixture.c needs pragma weak <perlinger@ntp.org>
  - removed unnecessary & harmful decls of 'setUp()' & 'tearDown()'
* [Bug 3019] Windows: ERROR_HOST_UNREACHABLE block packet processing. DMayer
* [Bug 2998] sntp/tests/packetProcessing.c broken without openssl. JPerlinger
* [Bug 2961] sntp/tests/packetProcessing.c assumes AUTOKEY.  HStenn.
* [Bug 2959] refclock_jupiter: gps week correction <perlinger@ntp.org>
  - fixed GPS week expansion to work based on build date. Special thanks
    to Craig Leres for initial patch and testing.
* [Bug 2951] ntpd tests fail: multiple definition of `send_via_ntp_signd'
  - fixed Makefile.am <perlinger@ntp.org>
* [Bug 2689] ATOM driver processes last PPS pulse at startup,
             even if it is very old <perlinger@ntp.org>
  - make sure PPS source is alive before processing samples
  - improve stability close to the 500ms phase jump (phase gate)
* Fix typos in include/ntp.h.
* Shim X509_get_signature_nid() if needed
* git author attribution cleanup
* bk ignore file cleanup
* remove locks in Windows IO, use rpc-like thread synchronisation instead

---
NTP 4.2.8p8 (Harlan Stenn <stenn@ntp.org>, 2016/06/02) 

Focus: Security, Bug fixes, enhancements.

Severity: HIGH

In addition to bug fixes and enhancements, this release fixes the
following 1 high- and 4 low-severity vulnerabilities:

* CRYPTO_NAK crash
   Date Resolved: 02 June 2016; Dev (4.3.93) 02 June 2016
   References: Sec 3046 / CVE-2016-4957 / VU#321640
   Affects: ntp-4.2.8p7, and ntp-4.3.92.
   CVSS2: HIGH 7.8 (AV:N/AC:L/Au:N/C:N/I:N/A:C)
   CVSS3: HIGH 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
   Summary: The fix for Sec 3007 in ntp-4.2.8p7 contained a bug that
	could cause ntpd to crash.
   Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p8, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        If you cannot upgrade from 4.2.8p7, the only other alternatives
	    are to patch your code or filter CRYPTO_NAK packets.
        Properly monitor your ntpd instances, and auto-restart ntpd
	    (without -g) if it stops running. 
   Credit: This weakness was discovered by Nicolas Edet of Cisco. 

* Bad authentication demobilizes ephemeral associations
   Date Resolved: 02 June 2016; Dev (4.3.93) 02 June 2016
   References: Sec 3045 / CVE-2016-4953 / VU#321640
   Affects: ntp-4, up to but not including ntp-4.2.8p8, and
	ntp-4.3.0 up to, but not including ntp-4.3.93.
   CVSS2: LOW 2.6 (AV:N/AC:H/Au:N/C:N/I:N/A:P)
   CVSS3: LOW 3.7 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
   Summary: An attacker who knows the origin timestamp and can send a
	spoofed packet containing a CRYPTO-NAK to an ephemeral peer
	target before any other response is sent can demobilize that
	association.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p8, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your ntpd instances. 
	Credit: This weakness was discovered by Miroslav Lichvar of Red Hat. 

* Processing spoofed server packets
   Date Resolved: 02 June 2016; Dev (4.3.93) 02 June 2016
   References: Sec 3044 / CVE-2016-4954 / VU#321640
   Affects: ntp-4, up to but not including ntp-4.2.8p8, and
	ntp-4.3.0 up to, but not including ntp-4.3.93.
   CVSS2: LOW 2.6 (AV:N/AC:H/Au:N/C:N/I:N/A:P)
   CVSS3: LOW 3.7 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
   Summary: An attacker who is able to spoof packets with correct origin
	timestamps from enough servers before the expected response
	packets arrive at the target machine can affect some peer
	variables and, for example, cause a false leap indication to be set.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p8, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your ntpd instances. 
   Credit: This weakness was discovered by Jakub Prokes of Red Hat. 

* Autokey association reset
   Date Resolved: 02 June 2016; Dev (4.3.93) 02 June 2016
   References: Sec 3043 / CVE-2016-4955 / VU#321640
   Affects: ntp-4, up to but not including ntp-4.2.8p8, and
	ntp-4.3.0 up to, but not including ntp-4.3.93.
   CVSS2: LOW 2.6 (AV:N/AC:H/Au:N/C:N/I:N/A:P)
   CVSS3: LOW 3.7 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
   Summary: An attacker who is able to spoof a packet with a correct
	origin timestamp before the expected response packet arrives at
	the target machine can send a CRYPTO_NAK or a bad MAC and cause
	the association's peer variables to be cleared. If this can be
	done often enough, it will prevent that association from working.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p8, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your ntpd instances. 
   Credit: This weakness was discovered by Miroslav Lichvar of Red Hat. 
 
* Broadcast interleave
   Date Resolved: 02 June 2016; Dev (4.3.93) 02 June 2016
   References: Sec 3042 / CVE-2016-4956 / VU#321640
   Affects: ntp-4, up to but not including ntp-4.2.8p8, and
   	ntp-4.3.0 up to, but not including ntp-4.3.93.
   CVSS2: LOW 2.6 (AV:N/AC:H/Au:N/C:N/I:N/A:P)
   CVSS3: LOW 3.7 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
   Summary: The fix for NtpBug2978 does not cover broadcast associations,
   	so broadcast clients can be triggered to flip into interleave mode.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p8, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your ntpd instances. 
   Credit: This weakness was discovered by Miroslav Lichvar of Red Hat. 

Other fixes:
* [Bug 3038] NTP fails to build in VS2015. perlinger@ntp.org
  - provide build environment
  - 'wint_t' and 'struct timespec' defined by VS2015
  - fixed print()/scanf() format issues
* [Bug 3052] Add a .gitignore file.  Edmund Wong.
* [Bug 3054] miscopt.html documents the allan intercept in seconds. SWhite.
* [Bug 3058] fetch_timestamp() mishandles 64-bit alignment. Brian Utterback,
  JPerlinger, HStenn.
* Fix typo in ntp-wait and plot_summary.  HStenn.
* Make sure we have an "author" file for git imports.  HStenn.
* Update the sntp problem tests for MacOS.  HStenn.

---
NTP 4.2.8p7 (Harlan Stenn <stenn@ntp.org>, 2016/04/26) 

Focus: Security, Bug fixes, enhancements.

Severity: MEDIUM

When building NTP from source, there is a new configure option
available, --enable-dynamic-interleave.  More information on this below.

Also note that ntp-4.2.8p7 logs more "unexpected events" than previous
versions of ntp.  These events have almost certainly happened in the
past, it's just that they were silently counted and not logged.  With
the increasing awareness around security, we feel it's better to clearly
log these events to help detect abusive behavior.  This increased
logging can also help detect other problems, too.

In addition to bug fixes and enhancements, this release fixes the
following 9 low- and medium-severity vulnerabilities:

* Improve NTP security against buffer comparison timing attacks,
  AKA: authdecrypt-timing
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 2879 / CVE-2016-1550
   Affects: All ntp-4 releases up to, but not including 4.2.8p7, and
	4.3.0 up to, but not including 4.3.92
   CVSSv2: LOW 2.6 - (AV:L/AC:H/Au:N/C:P/I:P/A:N)
   CVSSv3: MED 4.0 - CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
   Summary: Packet authentication tests have been performed using
	memcmp() or possibly bcmp(), and it is potentially possible
	for a local or perhaps LAN-based attacker to send a packet with
	an authentication payload and indirectly observe how much of
	the digest has matched.
   Mitigation:
	Upgrade to 4.2.8p7, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page.
	Properly monitor your ntpd instances.
   Credit: This weakness was discovered independently by Loganaden
   	Velvindron, and Matthew Van Gundy and Stephen Gray of Cisco ASIG.

* Zero origin timestamp bypass: Additional KoD checks.
   References: Sec 2945 / Sec 2901 / CVE-2015-8138
   Affects: All ntp-4 releases up to, but not including 4.2.8p7,
   Summary: Improvements to the fixes incorporated in t 4.2.8p6 and 4.3.92.

* peer associations were broken by the fix for NtpBug2899
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 2952 / CVE-2015-7704
   Affects: All ntp-4 releases up to, but not including 4.2.8p7, and
   	4.3.0 up to, but not including 4.3.92
   CVSSv2: MED 4.3 - (AV:N/AC:M/Au:N/C:N/I:N/A:P)
   Summary: The fix for NtpBug2952 in ntp-4.2.8p5 to address broken peer
   	associations did not address all of the issues.
   Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p7, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        If you can't upgrade, use "server" associations instead of
	    "peer" associations.
        Monitor your ntpd instances. 
   Credit: This problem was discovered by Michael Tatarinov.

* Validate crypto-NAKs, AKA: CRYPTO-NAK DoS
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 3007 / CVE-2016-1547 / VU#718152
   Affects: All ntp-4 releases up to, but not including 4.2.8p7, and
	4.3.0 up to, but not including 4.3.92
   CVSS2: MED 4.3 - (AV:N/AC:M/Au:N/C:N/I:N/A:P)
   CVSS3: MED 3.7 - CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
   Summary: For ntp-4 versions up to but not including ntp-4.2.8p7, an
	off-path attacker can cause a preemptable client association to
	be demobilized by sending a crypto NAK packet to a victim client
	with a spoofed source address of an existing associated peer.
	This is true even if authentication is enabled.

	Furthermore, if the attacker keeps sending crypto NAK packets,
	for example one every second, the victim never has a chance to
	reestablish the association and synchronize time with that
	legitimate server.

	For ntp-4.2.8 thru ntp-4.2.8p6 there is less risk because more
	stringent checks are performed on incoming packets, but there
	are still ways to exploit this vulnerability in versions before
	ntp-4.2.8p7.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p7, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your =ntpd= instances
   Credit: This weakness was discovered by Stephen Gray and
   	Matthew Van Gundy of Cisco ASIG.

* ctl_getitem() return value not always checked
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 3008 / CVE-2016-2519
   Affects: All ntp-4 releases up to, but not including 4.2.8p7, and
	4.3.0 up to, but not including 4.3.92
   CVSSv2: MED 4.9 - (AV:N/AC:H/Au:S/C:N/I:N/A:C)
   CVSSv3: MED 4.2 - CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
   Summary: ntpq and ntpdc can be used to store and retrieve information
   	in ntpd. It is possible to store a data value that is larger
	than the size of the buffer that the ctl_getitem() function of
	ntpd uses to report the return value. If the length of the
	requested data value returned by ctl_getitem() is too large,
	the value NULL is returned instead. There are 2 cases where the
	return value from ctl_getitem() was not directly checked to make
	sure it's not NULL, but there are subsequent INSIST() checks
	that make sure the return value is not NULL. There are no data
	values ordinarily stored in ntpd that would exceed this buffer
	length. But if one has permission to store values and one stores
	a value that is "too large", then ntpd will abort if an attempt
	is made to read that oversized value.
    Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p7, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        Properly monitor your ntpd instances.
    Credit: This weakness was discovered by Yihan Lian of the Cloud
    	Security Team, Qihoo 360. 

* Crafted addpeer with hmode > 7 causes array wraparound with MATCH_ASSOC 
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 3009 / CVE-2016-2518 / VU#718152
   Affects: All ntp-4 releases up to, but not including 4.2.8p7, and
	4.3.0 up to, but not including 4.3.92
   CVSS2: LOW 2.1 - (AV:N/AC:H/Au:S/C:N/I:N/A:P)
   CVSS3: LOW 2.0 - CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L
   Summary: Using a crafted packet to create a peer association with
   	hmode > 7 causes the MATCH_ASSOC() lookup to make an
	out-of-bounds reference.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p7, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your ntpd instances
   Credit: This weakness was discovered by Yihan Lian of the Cloud
   	Security Team, Qihoo 360.

* remote configuration trustedkey/requestkey/controlkey values are not
	properly validated
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 3010 / CVE-2016-2517 / VU#718152
   Affects: All ntp-4 releases up to, but not including 4.2.8p7, and
	4.3.0 up to, but not including 4.3.92
   CVSS2: MED 4.9 - (AV:N/AC:H/Au:S/C:N/I:N/A:C)
   CVSS3: MED 4.2 - CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
   Summary: If ntpd was expressly configured to allow for remote
   	configuration, a malicious user who knows the controlkey for
	ntpq or the requestkey for ntpdc (if mode7 is expressly enabled)
	can create a session with ntpd and then send a crafted packet to
	ntpd that will change the value of the trustedkey, controlkey,
	or requestkey to a value that will prevent any subsequent
	authentication with ntpd until ntpd is restarted.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p7, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your =ntpd= instances
   Credit: This weakness was discovered by Yihan Lian of the Cloud
   	Security Team, Qihoo 360.

* Duplicate IPs on unconfig directives will cause an assertion botch in ntpd
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 3011 / CVE-2016-2516 / VU#718152
   Affects: All ntp-4 releases up to, but not including 4.2.8p7, and
   	4.3.0 up to, but not including 4.3.92
   CVSS2: MED 6.3 - (AV:N/AC:M/Au:S/C:N/I:N/A:C)
   CVSS3: MED 4.2 - CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
   Summary: If ntpd was expressly configured to allow for remote
   	configuration, a malicious user who knows the controlkey for
	ntpq or the requestkey for ntpdc (if mode7 is expressly enabled)
	can create a session with ntpd and if an existing association is
	unconfigured using the same IP twice on the unconfig directive
	line, ntpd will abort.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p7, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	Properly monitor your ntpd instances
   Credit: This weakness was discovered by Yihan Lian of the Cloud
   	Security Team, Qihoo 360.

* Refclock impersonation vulnerability
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 3020 / CVE-2016-1551
   Affects: On a very limited number of OSes, all NTP releases up to but
	not including 4.2.8p7, and 4.3.0 up to but not including 4.3.92.
	By "very limited number of OSes" we mean no general-purpose OSes
	have yet been identified that have this vulnerability.
   CVSSv2: LOW 2.6 - (AV:N/AC:H/Au:N/C:N/I:P/A:N)
   CVSSv3: LOW 3.7 - CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
   Summary: While most OSes implement martian packet filtering in their
   	network stack, at least regarding 127.0.0.0/8, some will allow
	packets claiming to be from 127.0.0.0/8 that arrive over a
	physical network. On these OSes, if ntpd is configured to use a
	reference clock an attacker can inject packets over the network
	that look like they are coming from that reference clock.
   Mitigation:
        Implement martian packet filtering and BCP-38.
        Configure ntpd to use an adequate number of time sources.
        Upgrade to 4.2.8p7, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
        If you are unable to upgrade and if you are running an OS that
	    has this vulnerability, implement martian packet filters and
	    lobby your OS vendor to fix this problem, or run your
	    refclocks on computers that use OSes that are not vulnerable
	    to these attacks and have your vulnerable machines get their
	    time from protected resources.
        Properly monitor your ntpd instances.
   Credit: This weakness was discovered by Matt Street and others of
   	Cisco ASIG. 

The following issues were fixed in earlier releases and contain
improvements in 4.2.8p7:

* Clients that receive a KoD should validate the origin timestamp field.
   References: Sec 2901 / CVE-2015-7704, CVE-2015-7705
   Affects: All ntp-4 releases up to, but not including 4.2.8p7,
   Summary: Improvements to the fixes incorporated into 4.2.8p4 and 4.3.77.

* Skeleton key: passive server with trusted key can serve time.
   References: Sec 2936 / CVE-2015-7974
   Affects: All ntp-4 releases up to, but not including 4.2.8p7,
   Summary: Improvements to the fixes incorporated in t 4.2.8p6 and 4.3.90.

Two other vulnerabilities have been reported, and the mitigations
for these are as follows:

* Interleave-pivot
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 2978 / CVE-2016-1548
   Affects: All ntp-4 releases.
   CVSSv2: MED 6.4 - (AV:N/AC:L/Au:N/C:N/I:P/A:P)
   CVSSv3: MED 7.2 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L
   Summary: It is possible to change the time of an ntpd client or deny
   	service to an ntpd client by forcing it to change from basic
	client/server mode to interleaved symmetric mode. An attacker
	can spoof a packet from a legitimate ntpd server with an origin
	timestamp that matches the peer->dst timestamp recorded for that
	server. After making this switch, the client will reject all
	future legitimate server responses. It is possible to force the
	victim client to move time after the mode has been changed.
	ntpq gives no indication that the mode has been switched.
   Mitigation:
        Implement BCP-38.
        Upgrade to 4.2.8p7, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page.  These
	    versions will not dynamically "flip" into interleave mode
	    unless configured to do so.
        Properly monitor your ntpd instances.
   Credit: This weakness was discovered by Miroslav Lichvar of RedHat
   	and separately by Jonathan Gardner of Cisco ASIG.

* Sybil vulnerability: ephemeral association attack
   Date Resolved: Stable (4.2.8p7) 26 Apr 2016; Dev (4.3.92) 26 Apr 2016
   References: Sec 3012 / CVE-2016-1549
   Affects: All ntp-4 releases up to, but not including 4.2.8p7, and
   	4.3.0 up to, but not including 4.3.92
   CVSSv2: LOW 3.5 - (AV:N/AC:M/Au:S/C:N/I:P/A:N)
   CVSS3v: MED 5.3 - CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
   Summary: ntpd can be vulnerable to Sybil attacks. If one is not using
   	the feature introduced in ntp-4.2.8p6 allowing an optional 4th
	field in the ntp.keys file to specify which IPs can serve time,
	a malicious authenticated peer can create arbitrarily-many
	ephemeral associations in order to win the clock selection of
	ntpd and modify a victim's clock.
   Mitigation:
        Implement BCP-38.
        Use the 4th field in the ntp.keys file to specify which IPs
	    can be time servers.
        Properly monitor your ntpd instances.
   Credit: This weakness was discovered by Matthew Van Gundy of Cisco ASIG. 

Other fixes:

* [Bug 2831]  Segmentation Fault in DNS lookup during startup. perlinger@ntp.org
  - fixed yet another race condition in the threaded resolver code.
* [Bug 2858] bool support.  Use stdbool.h when available.  HStenn.
* [Bug 2879] Improve NTP security against timing attacks. perlinger@ntp.org
  - integrated patches by Loganaden Velvidron <logan@ntp.org>
    with some modifications & unit tests
* [Bug 2960] async name resolution fixes for chroot() environments.
  Reinhard Max.
* [Bug 2994] Systems with HAVE_SIGNALED_IO fail to compile. perlinger@ntp.org
* [Bug 2995] Fixes to compile on Windows
* [Bug 2999] out-of-bounds access in 'is_safe_filename()'. perlinger@ntp.org
* [Bug 3013] Fix for ssl_init.c SHA1 test. perlinger@ntp.org
  - Patch provided by Ch. Weisgerber
* [Bug 3015] ntpq: config-from-file: "request contains an unprintable character"
  - A change related to [Bug 2853] forbids trailing white space in
    remote config commands. perlinger@ntp.org
* [Bug 3019] NTPD stops processing packets after ERROR_HOST_UNREACHABLE
  - report and patch from Aleksandr Kostikov.
  - Overhaul of Windows IO completion port handling. perlinger@ntp.org
* [Bug 3022] authkeys.c should be refactored. perlinger@ntp.org
  - fixed memory leak in access list (auth[read]keys.c)
  - refactored handling of key access lists (auth[read]keys.c)
  - reduced number of error branches (authreadkeys.c)
* [Bug 3023] ntpdate cannot correct dates in the future. perlinger@ntp.org
* [Bug 3030] ntpq needs a general way to specify refid output format.  HStenn.
* [Bug 3031] ntp broadcastclient unable to synchronize to an server
             when the time of server changed. perlinger@ntp.org
  - Check the initial delay calculation and reject/unpeer the broadcast
    server if the delay exceeds 50ms. Retry again after the next
    broadcast packet.
* [Bug 3036] autokey trips an INSIST in authistrustedip().  Harlan Stenn.
* Document ntp.key's optional IP list in authenetic.html.  Harlan Stenn.
* Update html/xleave.html documentation.  Harlan Stenn.
* Update ntp.conf documentation.  Harlan Stenn.
* Fix some Credit: attributions in the NEWS file.  Harlan Stenn.
* Fix typo in html/monopt.html.  Harlan Stenn.
* Add README.pullrequests.  Harlan Stenn.
* Cleanup to include/ntp.h.  Harlan Stenn.

New option to 'configure':

While looking in to the issues around Bug 2978, the "interleave pivot"
issue, it became clear that there are some intricate and unresolved
issues with interleave operations.  We also realized that the interleave
protocol was never added to the NTPv4 Standard, and it should have been.

Interleave mode was first released in July of 2008, and can be engaged
in two ways.  Any 'peer' and 'broadcast' lines in the ntp.conf file may
contain the 'xleave' option, which will expressly enable interlave mode
for that association.  Additionally, if a time packet arrives and is
found inconsistent with normal protocol behavior but has certain
characteristics that are compatible with interleave mode, NTP will
dynamically switch to interleave mode.  With sufficient knowledge, an
attacker can send a crafted forged packet to an NTP instance that
triggers only one side to enter interleaved mode.

To prevent this attack until we can thoroughly document, describe,
fix, and test the dynamic interleave mode, we've added a new
'configure' option to the build process:

 --enable-dynamic-interleave

This option controls whether or not NTP will, if conditions are right,
engage dynamic interleave mode.  Dynamic interleave mode is disabled by
default in ntp-4.2.8p7.

---
NTP 4.2.8p6 (Harlan Stenn <stenn@ntp.org>, 2016/01/20) 

Focus: Security, Bug fixes, enhancements.

Severity: MEDIUM

In addition to bug fixes and enhancements, this release fixes the
following 1 low- and 8 medium-severity vulnerabilities:

* Potential Infinite Loop in 'ntpq'
   Date Resolved: Stable (4.2.8p6) 19 Jan 2016; Dev (4.3.90) 19 Jan 2016
   References: Sec 2548 / CVE-2015-8158
   Affects: All ntp-4 releases up to, but not including 4.2.8p6, and
	4.3.0 up to, but not including 4.3.90
   CVSS2: (AV:N/AC:M/Au:N/C:N/I:N/A:P) Base Score: 4.3 - MEDIUM
   CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Base Score: 5.3 - MEDIUM
   Summary: 'ntpq' processes incoming packets in a loop in 'getresponse()'.
	The loop's only stopping conditions are receiving a complete and
	correct response or hitting a small number of error conditions.
	If the packet contains incorrect values that don't trigger one of
	the error conditions, the loop continues to receive new packets.
	Note well, this is an attack against an instance of 'ntpq', not
	'ntpd', and this attack requires the attacker to do one of the
	following:
	* Own a malicious NTP server that the client trusts
	* Prevent a legitimate NTP server from sending packets to
	    the 'ntpq' client
	* MITM the 'ntpq' communications between the 'ntpq' client
	    and the NTP server
   Mitigation:
	Upgrade to 4.2.8p6, or later, from the NTP Project Download Page
	or the NTP Public Services Project Download Page
   Credit: This weakness was discovered by Jonathan Gardner of Cisco ASIG.

* 0rigin: Zero Origin Timestamp Bypass
   Date Resolved: Stable (4.2.8p6) 19 Jan 2016; Dev (4.3.90) 19 Jan 2016
   References: Sec 2945 / CVE-2015-8138
   Affects: All ntp-4 releases up to, but not including 4.2.8p6, and
	4.3.0 up to, but not including 4.3.90
   CVSS2: (AV:N/AC:L/Au:N/C:N/I:P/A:N) Base Score: 5.0 - MEDIUM
   CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Base Score: 5.3 - MEDIUM
	(3.7 - LOW if you score AC:L)
   Summary: To distinguish legitimate peer responses from forgeries, a
	client attempts to verify a response packet by ensuring that the
	origin timestamp in the packet matches the origin timestamp it
	transmitted in its last request.  A logic error exists that
	allows packets with an origin timestamp of zero to bypass this
	check whenever there is not an outstanding request to the server.
   Mitigation:
	Configure 'ntpd' to get time from multiple sources.
	Upgrade to 4.2.8p6, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page.
	Monitor your 'ntpd= instances.
   Credit: This weakness was discovered by Matthey Van Gundy and
	Jonathan Gardner of Cisco ASIG.

* Stack exhaustion in recursive traversal of restriction list
   Date Resolved: Stable (4.2.8p6) 19 Jan 2016
   References: Sec 2940 / CVE-2015-7978
   Affects: All ntp-4 releases up to, but not including 4.2.8p6, and
	4.3.0 up to, but not including 4.3.90
   CVSS: (AV:N/AC:M/Au:N/C:N/I:N/A:P) Base Score: 4.3 - MEDIUM
   Summary: An unauthenticated 'ntpdc reslist' command can cause a
   	segmentation fault in ntpd by exhausting the call stack.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p6, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page.
	If you are unable to upgrade:
            In ntp-4.2.8, mode 7 is disabled by default. Don't enable it.
	    If you must enable mode 7:
		configure the use of a 'requestkey' to control who can
		    issue mode 7 requests.
		configure 'restrict noquery' to further limit mode 7
		    requests to trusted sources.
		Monitor your ntpd instances.
   Credit: This weakness was discovered by Stephen Gray at Cisco ASIG.

* Off-path Denial of Service (!DoS) attack on authenticated broadcast mode
   Date Resolved: Stable (4.2.8p6) 19 Jan 2016; Dev (4.3.90) 19 Jan 2016
   References: Sec 2942 / CVE-2015-7979
   Affects: All ntp-4 releases up to, but not including 4.2.8p6, and
	4.3.0 up to, but not including 4.3.90
   CVSS: (AV:N/AC:M/Au:N/C:N/I:P/A:P) Base Score: 5.8
   Summary: An off-path attacker can send broadcast packets with bad
	authentication (wrong key, mismatched key, incorrect MAC, etc)
	to broadcast clients. It is observed that the broadcast client
	tears down the association with the broadcast server upon
	receiving just one bad packet.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p6, or later, from the NTP Project Download Page
	or the NTP Public Services Project Download Page.
	Monitor your 'ntpd' instances.
	If this sort of attack is an active problem for you, you have
	    deeper problems to investigate.  In this case also consider
	    having smaller NTP broadcast domains.
   Credit: This weakness was discovered by Aanchal Malhotra of Boston
   	University.

* reslist NULL pointer dereference
   Date Resolved: Stable (4.2.8p6) 19 Jan 2016; Dev (4.3.90) 19 Jan 2016
   References: Sec 2939 / CVE-2015-7977
   Affects: All ntp-4 releases up to, but not including 4.2.8p6, and
	4.3.0 up to, but not including 4.3.90
   CVSS: (AV:N/AC:M/Au:N/C:N/I:N/A:P) Base Score: 4.3 - MEDIUM
   Summary: An unauthenticated 'ntpdc reslist' command can cause a
	segmentation fault in ntpd by causing a NULL pointer dereference.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p6, or later, from NTP Project Download Page or
	the NTP Public Services Project Download Page.
	If you are unable to upgrade:
	    mode 7 is disabled by default.  Don't enable it.
	    If you must enable mode 7:
		configure the use of a 'requestkey' to control who can
		    issue mode 7 requests.
		configure 'restrict noquery' to further limit mode 7
		    requests to trusted sources. 
	Monitor your ntpd instances.
   Credit: This weakness was discovered by Stephen Gray of Cisco ASIG.

* 'ntpq saveconfig' command allows dangerous characters in filenames.
   Date Resolved: Stable (4.2.8p6) 19 Jan 2016; Dev (4.3.90) 19 Jan 2016
   References: Sec 2938 / CVE-2015-7976
   Affects: All ntp-4 releases up to, but not including 4.2.8p6, and
	4.3.0 up to, but not including 4.3.90
   CVSS: (AV:N/AC:L/Au:S/C:N/I:P/A:N) Base Score: 4.0 - MEDIUM
   Summary: The ntpq saveconfig command does not do adequate filtering
   	of special characters from the supplied filename.
	Note well: The ability to use the saveconfig command is controlled
	by the 'restrict nomodify' directive, and the recommended default
	configuration is to disable this capability.  If the ability to
	execute a 'saveconfig' is required, it can easily (and should) be
	limited and restricted to a known small number of IP addresses.
   Mitigation:
	Implement BCP-38.
	use 'restrict default nomodify' in your 'ntp.conf' file.
	Upgrade to 4.2.8p6, or later, from the NTP Project Download Page.
	If you are unable to upgrade:
	    build NTP with 'configure --disable-saveconfig' if you will
	    	never need this capability, or
	    use 'restrict default nomodify' in your 'ntp.conf' file.  Be
		careful about what IPs have the ability to send 'modify'
		requests to 'ntpd'.
	Monitor your ntpd instances.
	'saveconfig' requests are logged to syslog - monitor your syslog files.
   Credit: This weakness was discovered by Jonathan Gardner of Cisco ASIG.

* nextvar() missing length check in ntpq
   Date Resolved: Stable (4.2.8p6) 19 Jan 2016; Dev (4.3.90) 19 Jan 2016
   References: Sec 2937 / CVE-2015-7975
   Affects: All ntp-4 releases up to, but not including 4.2.8p6, and
	4.3.0 up to, but not including 4.3.90
   CVSS: (AV:L/AC:H/Au:N/C:N/I:N/A:P) Base Score: 1.2 - LOW
	If you score A:C, this becomes 4.0.
   CVSSv3: (CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L) Base Score 2.9, LOW
   Summary: ntpq may call nextvar() which executes a memcpy() into the
	name buffer without a proper length check against its maximum
	length of 256 bytes. Note well that we're taking about ntpq here.
	The usual worst-case effect of this vulnerability is that the
	specific instance of ntpq will crash and the person or process
	that did this will have stopped themselves.
   Mitigation:
	Upgrade to 4.2.8p6, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page.
	If you are unable to upgrade:
	    If you have scripts that feed input to ntpq make sure there are
		some sanity checks on the input received from the "outside".
	    This is potentially more dangerous if ntpq is run as root. 
   Credit: This weakness was discovered by Jonathan Gardner at Cisco ASIG.

* Skeleton Key: Any trusted key system can serve time
   Date Resolved: Stable (4.2.8p6) 19 Jan 2016; Dev (4.3.90) 19 Jan 2016
   References: Sec 2936 / CVE-2015-7974
   Affects: All ntp-4 releases up to, but not including 4.2.8p6, and
	4.3.0 up to, but not including 4.3.90
   CVSS: (AV:N/AC:H/Au:S/C:N/I:C/A:N) Base Score: 4.9
   Summary: Symmetric key encryption uses a shared trusted key. The
	reported title for this issue was "Missing key check allows
	impersonation between authenticated peers" and the report claimed
	"A key specified only for one server should only work to
	authenticate that server, other trusted keys should be refused."
	Except there has never been any correlation between this trusted
	key and server v. clients machines and there has never been any
	way to specify a key only for one server. We have treated this as
	an enhancement request, and ntp-4.2.8p6 includes other checks and
	tests to strengthen clients against attacks coming from broadcast
	servers.
   Mitigation:
	Implement BCP-38.
	If this scenario represents a real or a potential issue for you,
	    upgrade to 4.2.8p6, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page, and
	    use the new field in the ntp.keys file that specifies the list
	    of IPs that are allowed to serve time. Note that this alone
	    will not protect against time packets with forged source IP
	    addresses, however other changes in ntp-4.2.8p6 provide
	    significant mitigation against broadcast attacks. MITM attacks
	    are a different story.
	If you are unable to upgrade:
	    Don't use broadcast mode if you cannot monitor your client
	    	servers.
	    If you choose to use symmetric keys to authenticate time
	    	packets in a hostile environment where ephemeral time
		servers can be created, or if it is expected that malicious
		time servers will participate in an NTP broadcast domain,
		limit the number of participating systems that participate
		in the shared-key group. 
	Monitor your ntpd instances. 
   Credit: This weakness was discovered by Matt Street of Cisco ASIG. 

* Deja Vu: Replay attack on authenticated broadcast mode
   Date Resolved: Stable (4.2.8p6) 19 Jan 2016; Dev (4.3.90) 19 Jan 2016
   References: Sec 2935 / CVE-2015-7973
   Affects: All ntp-4 releases up to, but not including 4.2.8p6, and
   	4.3.0 up to, but not including 4.3.90
   CVSS: (AV:A/AC:M/Au:N/C:N/I:P/A:P) Base Score: 4.3 - MEDIUM
   Summary: If an NTP network is configured for broadcast operations then
   	either a man-in-the-middle attacker or a malicious participant
	that has the same trusted keys as the victim can replay time packets.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p6, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page.
	If you are unable to upgrade:
	    Don't use broadcast mode if you cannot monitor your client servers.
	Monitor your ntpd instances.
   Credit: This weakness was discovered by Aanchal Malhotra of Boston
	University.

Other fixes:

* [Bug 2772] adj_systime overflows tv_usec. perlinger@ntp.org
* [Bug 2814] msyslog deadlock when signaled. perlinger@ntp.org
  - applied patch by shenpeng11@huawei.com with minor adjustments
* [Bug 2882] Look at ntp_request.c:list_peers_sum(). perlinger@ntp.org
* [Bug 2891] Deadlock in deferred DNS lookup framework. perlinger@ntp.org
* [Bug 2892] Several test cases assume IPv6 capabilities even when
             IPv6 is disabled in the build. perlinger@ntp.org
  - Found this already fixed, but validation led to cleanup actions.
* [Bug 2905] DNS lookups broken. perlinger@ntp.org
  - added limits to stack consumption, fixed some return code handling
* [Bug 2971] ntpq bails on ^C: select fails: Interrupted system call
  - changed stacked/nested handling of CTRL-C. perlinger@ntp.org
  - make CTRL-C work for retrieval and printing od MRU list. perlinger@ntp.org
* [Bug 2980] reduce number of warnings. perlinger@ntp.org
  - integrated several patches from Havard Eidnes (he@uninett.no)
* [Bug 2985] bogus calculation in authkeys.c perlinger@ntp.org
  - implement 'auth_log2()' using integer bithack instead of float calculation
* Make leapsec_query debug messages less verbose.  Harlan Stenn.

---
NTP 4.2.8p5 (Harlan Stenn <stenn@ntp.org>, 2016/01/07) 

Focus: Security, Bug fixes, enhancements.

Severity: MEDIUM

In addition to bug fixes and enhancements, this release fixes the
following medium-severity vulnerability:

* Small-step/big-step.  Close the panic gate earlier.
    References: Sec 2956, CVE-2015-5300
    Affects: All ntp-4 releases up to, but not including 4.2.8p5, and
	4.3.0 up to, but not including 4.3.78
    CVSS3: (AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:N/A:L) Base Score: 4.0, MEDIUM
    Summary: If ntpd is always started with the -g option, which is
	common and against long-standing recommendation, and if at the
	moment ntpd is restarted an attacker can immediately respond to
	enough requests from enough sources trusted by the target, which
	is difficult and not common, there is a window of opportunity
	where the attacker can cause ntpd to set the time to an
	arbitrary value. Similarly, if an attacker is able to respond
	to enough requests from enough sources trusted by the target,
	the attacker can cause ntpd to abort and restart, at which
	point it can tell the target to set the time to an arbitrary
	value if and only if ntpd was re-started against long-standing
	recommendation with the -g flag, or if ntpd was not given the
	-g flag, the attacker can move the target system's time by at
	most 900 seconds' time per attack.
    Mitigation:
	Configure ntpd to get time from multiple sources.
	Upgrade to 4.2.8p5, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page
	As we've long documented, only use the -g option to ntpd in
	    cold-start situations.
	Monitor your ntpd instances. 
    Credit: This weakness was discovered by Aanchal Malhotra,
	Isaac E. Cohen, and Sharon Goldberg at Boston University. 

    NOTE WELL: The -g flag disables the limit check on the panic_gate
	in ntpd, which is 900 seconds by default. The bug identified by
	the researchers at Boston University is that the panic_gate
	check was only re-enabled after the first change to the system
	clock that was greater than 128 milliseconds, by default. The
	correct behavior is that the panic_gate check should be
	re-enabled after any initial time correction.

	If an attacker is able to inject consistent but erroneous time
	responses to your systems via the network or "over the air",
	perhaps by spoofing radio, cellphone, or navigation satellite
	transmissions, they are in a great position to affect your
	system's clock. There comes a point where your very best
	defenses include:

	    Configure ntpd to get time from multiple sources.
	    Monitor your ntpd instances. 

Other fixes:

* Coverity submission process updated from Coverity 5 to Coverity 7.
  The NTP codebase has been undergoing regular Coverity scans on an
  ongoing basis since 2006.  As part of our recent upgrade from
  Coverity 5 to Coverity 7, Coverity identified 16 nits in some of
  the newly-written Unity test programs.  These were fixed.
* [Bug 2829] Clean up pipe_fds in ntpd.c  perlinger@ntp.org
* [Bug 2887] stratum -1 config results as showing value 99
  - fudge stratum should only accept values [0..16]. perlinger@ntp.org
* [Bug 2932] Update leapsecond file info in miscopt.html.  CWoodbury, HStenn.
* [Bug 2934] tests/ntpd/t-ntp_scanner.c has a magic constant wired in.  HMurray
* [Bug 2944] errno is not preserved properly in ntpdate after sendto call.
  - applied patch by Christos Zoulas.  perlinger@ntp.org
* [Bug 2952] Peer associations broken by fix for Bug 2901/CVE-2015-7704.
* [Bug 2954] Version 4.2.8p4 crashes on startup on some OSes.
  - fixed data race conditions in threaded DNS worker. perlinger@ntp.org
  - limit threading warm-up to linux; FreeBSD bombs on it. perlinger@ntp.org
* [Bug 2957] 'unsigned int' vs 'size_t' format clash. perlinger@ntp.org
  - accept key file only if there are no parsing errors
  - fixed size_t/u_int format clash
  - fixed wrong use of 'strlcpy'
* [Bug 2958] ntpq: fatal error messages need a final newline. Craig Leres.
* [Bug 2962] truncation of size_t/ptrdiff_t on 64bit targets. perlinger@ntp.org
  - fixed several other warnings (cast-alignment, missing const, missing prototypes)
  - promote use of 'size_t' for values that express a size
  - use ptr-to-const for read-only arguments
  - make sure SOCKET values are not truncated (win32-specific)
  - format string fixes
* [Bug 2965] Local clock didn't work since 4.2.8p4.  Martin Burnicki.
* [Bug 2967] ntpdate command suffers an assertion failure
  - fixed ntp_rfc2553.c to return proper address length. perlinger@ntp.org
* [Bug 2969]  Seg fault from ntpq/mrulist when looking at server with
              lots of clients. perlinger@ntp.org
* [Bug 2971] ntpq bails on ^C: select fails: Interrupted system call
  - changed stacked/nested handling of CTRL-C. perlinger@ntp.org
* Unity cleanup for FreeBSD-6.4.  Harlan Stenn.
* Unity test cleanup.  Harlan Stenn.
* Libevent autoconf pthread fixes for FreeBSD-10.  Harlan Stenn.
* Header cleanup in tests/sandbox/uglydate.c.  Harlan Stenn.
* Header cleanup in tests/libntp/sfptostr.c.  Harlan Stenn.
* Quiet a warning from clang.  Harlan Stenn.

---
NTP 4.2.8p4 (Harlan Stenn <stenn@ntp.org>, 2015/10/21) 

Focus: Security, Bug fixes, enhancements.

Severity: MEDIUM

In addition to bug fixes and enhancements, this release fixes the
following 13 low- and medium-severity vulnerabilities:

* Incomplete vallen (value length) checks in ntp_crypto.c, leading
  to potential crashes or potential code injection/information leakage.

    References: Sec 2899, Sec 2671, CVE-2015-7691, CVE-2015-7692, CVE-2015-7702
    Affects: All ntp-4 releases up to, but not including 4.2.8p4,
    	and 4.3.0 up to, but not including 4.3.77
    CVSS: (AV:N/AC:H/Au:M/C:N/I:N/A:C) Base Score: 4.6
    Summary: The fix for CVE-2014-9750 was incomplete in that there were
    	certain code paths where a packet with particular autokey operations
	that contained malicious data was not always being completely
	validated. Receipt of these packets can cause ntpd to crash.
    Mitigation:
        Don't use autokey.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page
	Monitor your ntpd instances. 
	Credit: This weakness was discovered by Tenable Network Security. 

* Clients that receive a KoD should validate the origin timestamp field.

    References: Sec 2901 / CVE-2015-7704, CVE-2015-7705
    Affects: All ntp-4 releases up to, but not including 4.2.8p4,
	and 4.3.0 up to, but not including 4.3.77
    CVSS: (AV:N/AC:M/Au:N/C:N/I:N/A:P) Base Score: 4.3-5.0 at worst
    Summary: An ntpd client that honors Kiss-of-Death responses will honor
    	KoD messages that have been forged by an attacker, causing it to
	delay or stop querying its servers for time updates. Also, an
	attacker can forge packets that claim to be from the target and
	send them to servers often enough that a server that implements
	KoD rate limiting will send the target machine a KoD response to
	attempt to reduce the rate of incoming packets, or it may also
	trigger a firewall block at the server for packets from the target
	machine. For either of these attacks to succeed, the attacker must
	know what servers the target is communicating with. An attacker
	can be anywhere on the Internet and can frequently learn the
	identity of the target's time source by sending the target a
	time query.
    Mitigation:
        Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download Page
	    or the NTP Public Services Project Download Page
	If you can't upgrade, restrict who can query ntpd to learn who
	    its servers are, and what IPs are allowed to ask your system
	    for the time. This mitigation is heavy-handed.
	Monitor your ntpd instances. 
    Note:
    	4.2.8p4 protects against the first attack. For the second attack,
    	all we can do is warn when it is happening, which we do in 4.2.8p4.
    Credit: This weakness was discovered by Aanchal Malhotra,
    	Issac E. Cohen, and Sharon Goldberg of Boston University. 

* configuration directives to change "pidfile" and "driftfile" should
  only be allowed locally. 

  References: Sec 2902 / CVE-2015-5196
  Affects: All ntp-4 releases up to, but not including 4.2.8p4,
	and 4.3.0 up to, but not including 4.3.77
   CVSS: (AV:N/AC:H/Au:M/C:N/I:C/A:C) Base Score: 6.2 worst case
   Summary: If ntpd is configured to allow for remote configuration,
	and if the (possibly spoofed) source IP address is allowed to
	send remote configuration requests, and if the attacker knows
	the remote configuration password, it's possible for an attacker
	to use the "pidfile" or "driftfile" directives to potentially
	overwrite other files.
   Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page
	If you cannot upgrade, don't enable remote configuration.
	If you must enable remote configuration and cannot upgrade,
	    remote configuration of NTF's ntpd requires:
	    - an explicitly configured trustedkey, and you should also
	    	configure a controlkey.
	    - access from a permitted IP. You choose the IPs.
	    - authentication. Don't disable it. Practice secure key safety. 
	Monitor your ntpd instances. 
   Credit: This weakness was discovered by Miroslav Lichvar of Red Hat. 

* Slow memory leak in CRYPTO_ASSOC 

  References: Sec 2909 / CVE-2015-7701
  Affects: All ntp-4 releases that use autokey up to, but not
    including 4.2.8p4, and 4.3.0 up to, but not including 4.3.77
  CVSS: (AV:N/AC:H/Au:M/C:N/I:N/A:C) Base Score: 0.0 best/usual case,
  	4.6 otherwise
  Summary: If ntpd is configured to use autokey, then an attacker can
	send packets to ntpd that will, after several days of ongoing
	attack, cause it to run out of memory.
  Mitigation:
	Don't use autokey.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page
	Monitor your ntpd instances. 
  Credit: This weakness was discovered by Tenable Network Security. 

* mode 7 loop counter underrun

  References:  Sec 2913 / CVE-2015-7848 / TALOS-CAN-0052
  Affects: All ntp-4 releases up to, but not including 4.2.8p4,
  	and 4.3.0 up to, but not including 4.3.77
  CVSS: (AV:N/AC:H/Au:M/C:N/I:N/A:C) Base Score: 4.6
  Summary: If ntpd is configured to enable mode 7 packets, and if the
	use of mode 7 packets is not properly protected thru the use of
	the available mode 7 authentication and restriction mechanisms,
	and if the (possibly spoofed) source IP address is allowed to
	send mode 7 queries, then an attacker can send a crafted packet
	to ntpd that will cause it to crash.
  Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page.
	      If you are unable to upgrade:
	In ntp-4.2.8, mode 7 is disabled by default. Don't enable it.
	If you must enable mode 7:
	    configure the use of a requestkey to control who can issue
		mode 7 requests.
	    configure restrict noquery to further limit mode 7 requests
		to trusted sources. 
	Monitor your ntpd instances. 
Credit: This weakness was discovered by Aleksandar Nikolic of Cisco Talos. 

* memory corruption in password store

  References: Sec 2916 / CVE-2015-7849 / TALOS-CAN-0054
  Affects: All ntp-4 releases up to, but not including 4.2.8p4, and 4.3.0 up to, but not including 4.3.77
  CVSS: (AV:N/AC:H/Au:M/C:N/I:C/A:C) Base Score: 6.8, worst case
  Summary: If ntpd is configured to allow remote configuration, and if
	the (possibly spoofed) source IP address is allowed to send
	remote configuration requests, and if the attacker knows the
	remote configuration password or if ntpd was configured to
	disable authentication, then an attacker can send a set of
	packets to ntpd that may cause a crash or theoretically
	perform a code injection attack.
  Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page.
	If you are unable to upgrade, remote configuration of NTF's
	    ntpd requires:
		an explicitly configured "trusted" key. Only configure
			this if you need it.
		access from a permitted IP address. You choose the IPs.
		authentication. Don't disable it. Practice secure key safety. 
	Monitor your ntpd instances. 
  Credit: This weakness was discovered by Yves Younan of Cisco Talos. 

* Infinite loop if extended logging enabled and the logfile and
  keyfile are the same.

    References: Sec 2917 / CVE-2015-7850 / TALOS-CAN-0055
    Affects: All ntp-4 releases up to, but not including 4.2.8p4,
	and 4.3.0 up to, but not including 4.3.77
    CVSS: (AV:N/AC:H/Au:M/C:N/I:N/A:C) Base Score: 4.6, worst case
    Summary: If ntpd is configured to allow remote configuration, and if
	the (possibly spoofed) source IP address is allowed to send
	remote configuration requests, and if the attacker knows the
	remote configuration password or if ntpd was configured to
	disable authentication, then an attacker can send a set of
	packets to ntpd that will cause it to crash and/or create a
	potentially huge log file. Specifically, the attacker could
	enable extended logging, point the key file at the log file,
	and cause what amounts to an infinite loop.
    Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page.
	If you are unable to upgrade, remote configuration of NTF's ntpd
	  requires:
            an explicitly configured "trusted" key. Only configure this
	    	if you need it.
            access from a permitted IP address. You choose the IPs.
            authentication. Don't disable it. Practice secure key safety. 
        Monitor your ntpd instances. 
    Credit: This weakness was discovered by Yves Younan of Cisco Talos. 

* Potential path traversal vulnerability in the config file saving of
  ntpd on VMS.

  References: Sec 2918 / CVE-2015-7851 / TALOS-CAN-0062
  Affects: All ntp-4 releases running under VMS up to, but not
	including 4.2.8p4, and 4.3.0 up to, but not including 4.3.77
  CVSS: (AV:N/AC:H/Au:M/C:N/I:P/A:C) Base Score: 5.2, worst case
  Summary: If ntpd is configured to allow remote configuration, and if
	the (possibly spoofed) IP address is allowed to send remote
	configuration requests, and if the attacker knows the remote
	configuration password or if ntpd was configured to disable
	authentication, then an attacker can send a set of packets to
	ntpd that may cause ntpd to overwrite files.
  Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page.
	If you are unable to upgrade, remote configuration of NTF's ntpd
	    requires:
		an explicitly configured "trusted" key. Only configure
			this if you need it.
		access from permitted IP addresses. You choose the IPs.
		authentication. Don't disable it. Practice key security safety. 
        Monitor your ntpd instances. 
    Credit: This weakness was discovered by Yves Younan of Cisco Talos. 

* ntpq atoascii() potential memory corruption

  References: Sec 2919 / CVE-2015-7852 / TALOS-CAN-0063
  Affects: All ntp-4 releases running up to, but not including 4.2.8p4,
	and 4.3.0 up to, but not including 4.3.77
  CVSS: (AV:N/AC:H/Au:N/C:N/I:P/A:P) Base Score: 4.0, worst case
  Summary: If an attacker can figure out the precise moment that ntpq
	is listening for data and the port number it is listening on or
	if the attacker can provide a malicious instance ntpd that
	victims will connect to then an attacker can send a set of
	crafted mode 6 response packets that, if received by ntpq,
	can cause ntpq to crash.
  Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page.
	If you are unable to upgrade and you run ntpq against a server
	    and ntpq crashes, try again using raw mode. Build or get a
	    patched ntpq and see if that fixes the problem. Report new
	    bugs in ntpq or abusive servers appropriately.
	If you use ntpq in scripts, make sure ntpq does what you expect
	    in your scripts. 
  Credit: This weakness was discovered by Yves Younan and
  	Aleksander Nikolich of Cisco Talos. 

* Invalid length data provided by a custom refclock driver could cause
  a buffer overflow. 

  References: Sec 2920 / CVE-2015-7853 / TALOS-CAN-0064
  Affects: Potentially all ntp-4 releases running up to, but not
	including 4.2.8p4, and 4.3.0 up to, but not including 4.3.77
	that have custom refclocks
  CVSS: (AV:L/AC:H/Au:M/C:C/I:C/A:C) Base Score: 0.0 usual case,
	5.9 unusual worst case
  Summary: A negative value for the datalen parameter will overflow a
	data buffer. NTF's ntpd driver implementations always set this
	value to 0 and are therefore not vulnerable to this weakness.
	If you are running a custom refclock driver in ntpd and that
	driver supplies a negative value for datalen (no custom driver
	of even minimal competence would do this) then ntpd would
	overflow a data buffer. It is even hypothetically possible
	in this case that instead of simply crashing ntpd the attacker
	could effect a code injection attack.
  Mitigation:
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page.
	If you are unable to upgrade:
		If you are running custom refclock drivers, make sure
			the signed datalen value is either zero or positive. 
	Monitor your ntpd instances. 
  Credit: This weakness was discovered by Yves Younan of Cisco Talos. 

* Password Length Memory Corruption Vulnerability

  References: Sec 2921 / CVE-2015-7854 / TALOS-CAN-0065
  Affects: All ntp-4 releases up to, but not including 4.2.8p4, and
  	4.3.0 up to, but not including 4.3.77
  CVSS: (AV:N/AC:H/Au:M/C:C/I:C/A:C) Base Score: 0.0 best case,
  	1.7 usual case, 6.8, worst case
  Summary: If ntpd is configured to allow remote configuration, and if
	the (possibly spoofed) source IP address is allowed to send
	remote configuration requests, and if the attacker knows the
	remote configuration password or if ntpd was (foolishly)
	configured to disable authentication, then an attacker can
	send a set of packets to ntpd that may cause it to crash,
	with the hypothetical possibility of a small code injection.
  Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page.
	If you are unable to upgrade, remote configuration of NTF's
	    ntpd requires:
		an explicitly configured "trusted" key. Only configure
			this if you need it.
		access from a permitted IP address. You choose the IPs.
		authentication. Don't disable it. Practice secure key safety. 
	Monitor your ntpd instances. 
  Credit: This weakness was discovered by Yves Younan and
  	Aleksander Nikolich of Cisco Talos. 

* decodenetnum() will ASSERT botch instead of returning FAIL on some
  bogus values.

  References: Sec 2922 / CVE-2015-7855
  Affects: All ntp-4 releases up to, but not including 4.2.8p4, and
	4.3.0 up to, but not including 4.3.77
  CVSS: (AV:N/AC:H/Au:M/C:N/I:N/A:C) Base Score: 4.6, worst case
  Summary: If ntpd is fed a crafted mode 6 or mode 7 packet containing
	an unusually long data value where a network address is expected,
	the decodenetnum() function will abort with an assertion failure
	instead of simply returning a failure condition.
  Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page.
	If you are unable to upgrade:
		mode 7 is disabled by default. Don't enable it.
		Use restrict noquery to limit who can send mode 6
			and mode 7 requests.
		Configure and use the controlkey and requestkey
			authentication directives to limit who can
			send mode 6 and mode 7 requests. 
	Monitor your ntpd instances. 
  Credit: This weakness was discovered by John D "Doug" Birdwell of IDA.org. 

* NAK to the Future: Symmetric association authentication bypass via
  crypto-NAK.

  References: Sec 2941 / CVE-2015-7871
  Affects: All ntp-4 releases between 4.2.5p186 up to but not including
  	4.2.8p4, and 4.3.0 up to but not including 4.3.77
  CVSS: (AV:N/AC:L/Au:N/C:N/I:P/A:P) Base Score: 6.4
  Summary: Crypto-NAK packets can be used to cause ntpd to accept time
	from unauthenticated ephemeral symmetric peers by bypassing the
	authentication required to mobilize peer associations. This
	vulnerability appears to have been introduced in ntp-4.2.5p186
	when the code handling mobilization of new passive symmetric
	associations (lines 1103-1165) was refactored.
  Mitigation:
	Implement BCP-38.
	Upgrade to 4.2.8p4, or later, from the NTP Project Download
	    Page or the NTP Public Services Project Download Page.
	If you are unable to upgrade:
		Apply the patch to the bottom of the "authentic" check
			block around line 1136 of ntp_proto.c. 
	Monitor your ntpd instances. 
  Credit: This weakness was discovered by Matthew Van Gundy of Cisco ASIG. 

Backward-Incompatible changes:
* [Bug 2817] Default on Linux is now "rlimit memlock -1".
  While the general default of 32M is still the case, under Linux
  the default value has been changed to -1 (do not lock ntpd into
  memory).  A value of 0 means "lock ntpd into memory with whatever
  memory it needs." If your ntp.conf file has an explicit "rlimit memlock"
  value in it, that value will continue to be used.

* [Bug 2886] Misspelling: "outlyer" should be "outlier".
  If you've written a script that looks for this case in, say, the
  output of ntpq, you probably want to change your regex matches
  from 'outlyer' to 'outl[iy]er'.

New features in this release:
* 'rlimit memlock' now has finer-grained control.  A value of -1 means
  "don't lock ntpd into memore".  This is the default for Linux boxes.
  A value of 0 means "lock ntpd into memory" with no limits.  Otherwise
  the value is the number of megabytes of memory to lock.  The default
  is 32 megabytes.

* The old Google Test framework has been replaced with a new framework,
  based on http://www.throwtheswitch.org/unity/ .

Bug Fixes and Improvements:
* [Bug 2332] (reopened) Exercise thread cancellation once before dropping
  privileges and limiting resources in NTPD removes the need to link
  forcefully against 'libgcc_s' which does not always work. J.Perlinger
* [Bug 2595] ntpdate man page quirks.  Hal Murray, Harlan Stenn.
* [Bug 2625] Deprecate flag1 in local refclock.  Hal Murray, Harlan Stenn.
* [Bug 2817] Stop locking ntpd into memory by default under Linux.  H.Stenn.
* [Bug 2821] minor build issues: fixed refclock_gpsdjson.c.  perlinger@ntp.org
* [Bug 2823] ntpsweep with recursive peers option doesn't work.  H.Stenn.
* [Bug 2849] Systems with more than one default route may never
  synchronize.  Brian Utterback.  Note that this patch might need to
  be reverted once Bug 2043 has been fixed.
* [Bug 2864] 4.2.8p3 fails to compile on Windows. Juergen Perlinger
* [Bug 2866] segmentation fault at initgroups().  Harlan Stenn.
* [Bug 2867] ntpd with autokey active crashed by 'ntpq -crv'. J.Perlinger
* [Bug 2873] libevent should not include .deps/ in the tarball.  H.Stenn
* [Bug 2874] Don't distribute generated sntp/tests/fileHandlingTest.h. H.Stenn
* [Bug 2875] sntp/Makefile.am: Get rid of DIST_SUBDIRS.  libevent must
  be configured for the distribution targets.  Harlan Stenn.
* [Bug 2883] ntpd crashes on exit with empty driftfile.  Miroslav Lichvar.
* [Bug 2886] Mis-spelling: "outlyer" should be "outlier".  dave@horsfall.org
* [Bug 2888] streamline calendar functions.  perlinger@ntp.org
* [Bug 2889] ntp-dev-4.3.67 does not build on Windows.  perlinger@ntp.org
* [Bug 2890] Ignore ENOBUFS on routing netlink socket.  Konstantin Khlebnikov.
* [Bug 2906] make check needs better support for pthreads.  Harlan Stenn.
* [Bug 2907] dist* build targets require our libevent/ to be enabled.  HStenn.
* [Bug 2912] no munlockall() under Windows.  David Taylor, Harlan Stenn.
* libntp/emalloc.c: Remove explicit include of stdint.h.  Harlan Stenn.
* Put Unity CPPFLAGS items in unity_config.h.  Harlan Stenn.
* tests/ntpd/g_leapsec.cpp typo fix.  Harlan Stenn.
* Phase 1 deprecation of google test in sntp/tests/.  Harlan Stenn.
* On some versions of HP-UX, inttypes.h does not include stdint.h.  H.Stenn.
* top_srcdir can change based on ntp v. sntp.  Harlan Stenn.
* sntp/tests/ function parameter list cleanup.  Damir Tomić.
* tests/libntp/ function parameter list cleanup.  Damir Tomić.
* tests/ntpd/ function parameter list cleanup.  Damir Tomić.
* sntp/unity/unity_config.h: handle stdint.h.  Harlan Stenn.
* sntp/unity/unity_internals.h: handle *INTPTR_MAX on old Solaris.  H.Stenn.
* tests/libntp/timevalops.c and timespecops.c fixed error printing.  D.Tomić.
* tests/libntp/ improvements in code and fixed error printing.  Damir Tomić.
* tests/libntp: a_md5encrypt.c, authkeys.c, buftvtots.c, calendar.c, caljulian.c,
  caltontp.c, clocktime.c, humandate.c, hextolfp.c, decodenetnum.c - fixed
  formatting; first declaration, then code (C90); deleted unnecessary comments;
  changed from sprintf to snprintf; fixed order of includes. Tomasz Flendrich
* tests/libntp/lfpfunc.c remove unnecessary include, remove old comments,
  fix formatting, cleanup. Tomasz Flendrich
* tests/libntp/lfptostr.c remove unnecessary include, add consts, fix formatting.
  Tomasz Flendrich
* tests/libntp/statestr.c remove empty functions, remove unnecessary include,
  fix formatting. Tomasz Flendrich
* tests/libntp/modetoa.c fixed formatting. Tomasz Flendrich
* tests/libntp/msyslog.c fixed formatting. Tomasz Flendrich
* tests/libntp/numtoa.c deleted unnecessary empty functions, fixed formatting.
  Tomasz Flendrich
* tests/libntp/numtohost.c added const, fixed formatting. Tomasz Flendrich
* tests/libntp/refnumtoa.c fixed formatting. Tomasz Flendrich
* tests/libntp/ssl_init.c fixed formatting. Tomasz Flendrich
* tests/libntp/tvtots.c fixed a bug, fixed formatting. Tomasz Flendrich
* tests/libntp/uglydate.c removed an unnecessary include. Tomasz Flendrich
* tests/libntp/vi64ops.c removed an unnecessary comment, fixed formatting.
* tests/libntp/ymd3yd.c removed an empty function and an unnecessary include,
fixed formatting. Tomasz Flendrich
* tests/libntp/timespecops.c fixed formatting, fixed the order of includes,
  removed unnecessary comments, cleanup. Tomasz Flendrich
* tests/libntp/timevalops.c fixed the order of includes, deleted unnecessary
  comments, cleanup. Tomasz Flendrich
* tests/libntp/sockaddrtest.h making it agree to NTP's conventions of formatting.
  Tomasz Flendrich
* tests/libntp/lfptest.h cleanup. Tomasz Flendrich
* tests/libntp/test-libntp.c fix formatting. Tomasz Flendrich
* sntp/tests/crypto.c is now using proper Unity's assertions, fixed formatting.
  Tomasz Flendrich
* sntp/tests/kodDatabase.c added consts, deleted empty function,
  fixed formatting. Tomasz Flendrich
* sntp/tests/kodFile.c cleanup, fixed formatting. Tomasz Flendrich
* sntp/tests/packetHandling.c is now using proper Unity's assertions,
  fixed formatting, deleted unused variable. Tomasz Flendrich
* sntp/tests/keyFile.c is now using proper Unity's assertions, fixed formatting.
  Tomasz Flendrich
* sntp/tests/packetProcessing.c changed from sprintf to snprintf,
  fixed formatting. Tomasz Flendrich
* sntp/tests/utilities.c is now using proper Unity's assertions, changed
  the order of includes, fixed formatting, removed unnecessary comments.
  Tomasz Flendrich
* sntp/tests/sntptest.h fixed formatting. Tomasz Flendrich
* sntp/tests/fileHandlingTest.h.in fixed a possible buffer overflow problem,
  made one function do its job, deleted unnecessary prints, fixed formatting.
  Tomasz Flendrich
* sntp/unity/Makefile.am added a missing header. Tomasz Flendrich
* sntp/unity/unity_config.h: Distribute it.  Harlan Stenn.
* sntp/libevent/evconfig-private.h: remove generated filefrom SCM.  H.Stenn.
* sntp/unity/Makefile.am: fix some broken paths.  Harlan Stenn.
* sntp/unity/unity.c: Clean up a printf().  Harlan Stenn.
* Phase 1 deprecation of google test in tests/libntp/.  Harlan Stenn.
* Don't build sntp/libevent/sample/.  Harlan Stenn.
* tests/libntp/test_caltontp needs -lpthread.  Harlan Stenn.
* br-flock: --enable-local-libevent.  Harlan Stenn.
* Wrote tests for ntpd/ntp_prio_q.c. Tomasz Flendrich
* scripts/lib/NTP/Util.pm: stratum output is version-dependent.  Harlan Stenn.
* Get rid of the NTP_ prefix on our assertion macros.  Harlan Stenn.
* Code cleanup.  Harlan Stenn.
* libntp/icom.c: Typo fix.  Harlan Stenn.
* util/ntptime.c: initialization nit.  Harlan Stenn.
* ntpd/ntp_peer.c:newpeer(): added a DEBUG_REQUIRE(srcadr).  Harlan Stenn.
* Add std_unity_tests to various Makefile.am files.  Harlan Stenn.
* ntpd/ntp_restrict.c: added a few assertions, created tests for this file.
  Tomasz Flendrich
* Changed progname to be const in many files - now it's consistent. Tomasz
  Flendrich
* Typo fix for GCC warning suppression.  Harlan Stenn.
* Added tests/ntpd/ntp_scanner.c test. Damir Tomić.
* Added declarations to all Unity tests, and did minor fixes to them.
  Reduced the number of warnings by half. Damir Tomić.
* Updated generate_test_runner.rb and updated the sntp/unity/auto directory
  with the latest Unity updates from Mark. Damir Tomić.
* Retire google test - phase I.  Harlan Stenn.
* Unity test cleanup: move declaration of 'initializing'.  Harlan Stenn.
* Update the NEWS file.  Harlan Stenn.
* Autoconf cleanup.  Harlan Stenn.
* Unit test dist cleanup. Harlan Stenn.
* Cleanup various test Makefile.am files.  Harlan Stenn.
* Pthread autoconf macro cleanup.  Harlan Stenn.
* Fix progname definition in unity runner scripts.  Harlan Stenn.
* Clean trailing whitespace in tests/ntpd/Makefile.am.  Harlan Stenn.
* Update the patch for bug 2817.  Harlan Stenn.
* More updates for bug 2817.  Harlan Stenn.
* Fix bugs in tests/ntpd/ntp_prio_q.c.  Harlan Stenn.
* gcc on older HPUX may need +allowdups.  Harlan Stenn.
* Adding missing MCAST protection.  Harlan Stenn.
* Disable certain test programs on certain platforms.  Harlan Stenn.
* Implement --enable-problem-tests (on by default).  Harlan Stenn.
* build system tweaks.  Harlan Stenn.

---
NTP 4.2.8p3 (Harlan Stenn <stenn@ntp.org>, 2015/06/29) 

Focus: 1 Security fix.  Bug fixes and enhancements.  Leap-second improvements.

Severity: MEDIUM

Security Fix:

* [Sec 2853] Crafted remote config packet can crash some versions of
  ntpd.  Aleksis Kauppinen, Juergen Perlinger, Harlan Stenn.

Under specific circumstances an attacker can send a crafted packet to
cause a vulnerable ntpd instance to crash. This requires each of the
following to be true:

1) ntpd set up to allow remote configuration (not allowed by default), and
2) knowledge of the configuration password, and
3) access to a computer entrusted to perform remote configuration. 

This vulnerability is considered low-risk.

New features in this release:

Optional (disabled by default) support to have ntpd provide smeared
leap second time.  A specially built and configured ntpd will only
offer smeared time in response to client packets.  These response
packets will also contain a "refid" of 254.a.b.c, where the 24 bits
of a, b, and c encode the amount of smear in a 2:22 integer:fraction 
format.  See README.leapsmear and http://bugs.ntp.org/2855 for more
information.

   *IF YOU CHOOSE TO CONFIGURE NTPD TO PROVIDE LEAP SMEAR TIME*
   *BE SURE YOU DO NOT OFFER THAT TIME ON PUBLIC TIMESERVERS.*

We've imported the Unity test framework, and have begun converting
the existing google-test items to this new framework.  If you want
to write new tests or change old ones, you'll need to have ruby
installed.  You don't need ruby to run the test suite.

Bug Fixes and Improvements:

* CID 739725: Fix a rare resource leak in libevent/listener.c.
* CID 1295478: Quiet a pedantic potential error from the fix for Bug 2776.
* CID 1296235: Fix refclock_jjy.c and correcting type of the driver40-ja.html
* CID 1269537: Clean up a line of dead code in getShmTime().
* [Bug 1060] Buffer overruns in libparse/clk_rawdcf.c.  Helge Oldach.
* [Bug 2590] autogen-5.18.5.
* [Bug 2612] restrict: Warn when 'monitor' can't be disabled because
  of 'limited'.
* [Bug 2650] fix includefile processing.
* [Bug 2745] ntpd -x steps clock on leap second
   Fixed an initial-value problem that caused misbehaviour in absence of
   any leapsecond information.
   Do leap second stepping only of the step adjustment is beyond the
   proper jump distance limit and step correction is allowed at all.
* [Bug 2750] build for Win64
  Building for 32bit of loopback ppsapi needs def file
* [Bug 2776] Improve ntpq's 'help keytype'.
* [Bug 2778] Implement "apeers"  ntpq command to include associd.
* [Bug 2782] Refactor refclock_shm.c, add memory barrier protection.
* [Bug 2792] If the IFF_RUNNING interface flag is supported then an
  interface is ignored as long as this flag is not set since the
  interface is not usable (e.g., no link).
* [Bug 2794] Clean up kernel clock status reports.
* [Bug 2800] refclock_true.c true_debug() can't open debug log because
  of incompatible open/fdopen parameters.
* [Bug 2804] install-local-data assumes GNU 'find' semantics.
* [Bug 2805] ntpd fails to join multicast group.
* [Bug 2806] refclock_jjy.c supports the Telephone JJY.
* [Bug 2808] GPSD_JSON driver enhancements, step 1.
  Fix crash during cleanup if GPS device not present and char device.
  Increase internal token buffer to parse all JSON data, even SKY.
  Defer logging of errors during driver init until the first unit is
  started, so the syslog is not cluttered when the driver is not used.
  Various improvements, see http://bugs.ntp.org/2808 for details.
  Changed libjsmn to a more recent version.
* [Bug 2810] refclock_shm.c memory barrier code needs tweaks for QNX.
* [Bug 2813] HP-UX needs -D__STDC_VERSION__=199901L and limits.h.
* [Bug 2815] net-snmp before v5.4 has circular library dependencies.
* [Bug 2821] Add a missing NTP_PRINTF and a missing const.
* [Bug 2822] New leap column in sntp broke NTP::Util.pm.
* [Bug 2824] Convert update-leap to perl. (also see 2769)
* [Bug 2825] Quiet file installation in html/ .
* [Bug 2830] ntpd doesn't always transfer the correct TAI offset via autokey
   NTPD transfers the current TAI (instead of an announcement) now.
   This might still needed improvement.
   Update autokey data ASAP when 'sys_tai' changes.
   Fix unit test that was broken by changes for autokey update.
   Avoid potential signature length issue and use DPRINTF where possible
     in ntp_crypto.c.
* [Bug 2832] refclock_jjy.c supports the TDC-300.
* [Bug 2834] Correct a broken html tag in html/refclock.html
* [Bug 2836] DFC77 patches from Frank Kardel to make decoding more
  robust, and require 2 consecutive timestamps to be consistent.
* [Bug 2837] Allow a configurable DSCP value.
* [Bug 2837] add test for DSCP to ntpd/complete.conf.in
* [Bug 2842] Glitch in ntp.conf.def documentation stanza.
* [Bug 2842] Bug in mdoc2man.
* [Bug 2843] make check fails on 4.3.36
   Fixed compiler warnings about numeric range overflow
   (The original topic was fixed in a byplay to bug#2830)
* [Bug 2845] Harden memory allocation in ntpd.
* [Bug 2852] 'make check' can't find unity.h.  Hal Murray.
* [Bug 2854] Missing brace in libntp/strdup.c.  Masanari Iida.
* [Bug 2855] Parser fix for conditional leap smear code.  Harlan Stenn.
* [Bug 2855] Report leap smear in the REFID.  Harlan Stenn.
* [Bug 2855] Implement conditional leap smear code.  Martin Burnicki.
* [Bug 2856] ntpd should wait() on terminated child processes.  Paul Green.
* [Bug 2857] Stratus VOS does not support SIGIO.  Paul Green.
* [Bug 2859] Improve raw DCF77 robustness deconding.  Frank Kardel.
* [Bug 2860] ntpq ifstats sanity check is too stringent.  Frank Kardel.
* html/drivers/driver22.html: typo fix.  Harlan Stenn.
* refidsmear test cleanup.  Tomasz Flendrich.
* refidsmear function support and tests.  Harlan Stenn.
* sntp/tests/Makefile.am: remove g_nameresolution.cpp as it tested
  something that was only in the 4.2.6 sntp.  Harlan Stenn.
* Modified tests/bug-2803/Makefile.am so it builds Unity framework tests.
  Damir Tomić
* Modified tests/libtnp/Makefile.am so it builds Unity framework tests.
  Damir Tomić
* Modified sntp/tests/Makefile.am so it builds Unity framework tests.
  Damir Tomić
* tests/sandbox/smeartest.c: Harlan Stenn, Damir Tomic, Juergen Perlinger.
* Converted from gtest to Unity: tests/bug-2803/. Damir Tomić
* Converted from gtest to Unity: tests/libntp/ a_md5encrypt, atoint.c,
  atouint.c, authkeys.c, buftvtots.c, calendar.c, caljulian.c,
  calyearstart.c, clocktime.c, hextoint.c, lfpfunc.c, modetoa.c,
  numtoa.c, numtohost.c, refnumtoa.c, ssl_init.c, statestr.c,
  timespecops.c, timevalops.c, uglydate.c, vi64ops.c, ymd2yd.c.
  Damir Tomić
* Converted from gtest to Unity: sntp/tests/ kodDatabase.c, kodFile.c,
  networking.c, keyFile.c, utilities.cpp, sntptest.h,
  fileHandlingTest.h. Damir Tomić
* Initial support for experimental leap smear code.  Harlan Stenn.
* Fixes to sntp/tests/fileHandlingTest.h.in.  Harlan Stenn.
* Report select() debug messages at debug level 3 now.
* sntp/scripts/genLocInfo: treat raspbian as debian.
* Unity test framework fixes.
  ** Requires ruby for changes to tests.
* Initial support for PACKAGE_VERSION tests.
* sntp/libpkgver belongs in EXTRA_DIST, not DIST_SUBDIRS.
* tests/bug-2803/Makefile.am must distribute bug-2803.h.
* Add an assert to the ntpq ifstats code.
* Clean up the RLIMIT_STACK code.
* Improve the ntpq documentation around the controlkey keyid.
* ntpq.c cleanup.
* Windows port build cleanup.

---
NTP 4.2.8p2 (Harlan Stenn <stenn@ntp.org>, 2015/04/07) 

Focus: Security and Bug fixes, enhancements.

Severity: MEDIUM
 
In addition to bug fixes and enhancements, this release fixes the
following medium-severity vulnerabilities involving private key
authentication:

* [Sec 2779] ntpd accepts unauthenticated packets with symmetric key crypto.

    References: Sec 2779 / CVE-2015-1798 / VU#374268
    Affects: All NTP4 releases starting with ntp-4.2.5p99 up to but not
	including ntp-4.2.8p2 where the installation uses symmetric keys
	to authenticate remote associations.
    CVSS: (AV:A/AC:M/Au:N/C:P/I:P/A:P) Base Score: 5.4
    Date Resolved: Stable (4.2.8p2) 07 Apr 2015
    Summary: When ntpd is configured to use a symmetric key to authenticate
	a remote NTP server/peer, it checks if the NTP message
	authentication code (MAC) in received packets is valid, but not if
	there actually is any MAC included. Packets without a MAC are
	accepted as if they had a valid MAC. This allows a MITM attacker to
	send false packets that are accepted by the client/peer without
	having to know the symmetric key. The attacker needs to know the
	transmit timestamp of the client to match it in the forged reply
	and the false reply needs to reach the client before the genuine
	reply from the server. The attacker doesn't necessarily need to be
	relaying the packets between the client and the server.

	Authentication using autokey doesn't have this problem as there is
	a check that requires the key ID to be larger than NTP_MAXKEY,
	which fails for packets without a MAC.
    Mitigation:
        Upgrade to 4.2.8p2, or later, from the NTP Project Download Page
	or the NTP Public Services Project Download Page
        Configure ntpd with enough time sources and monitor it properly. 
    Credit: This issue was discovered by Miroslav Lichvar, of Red Hat. 

* [Sec 2781] Authentication doesn't protect symmetric associations against
  DoS attacks.

    References: Sec 2781 / CVE-2015-1799 / VU#374268
    Affects: All NTP releases starting with at least xntp3.3wy up to but
	not including ntp-4.2.8p2 where the installation uses symmetric
	key authentication.
    CVSS: (AV:A/AC:M/Au:N/C:P/I:P/A:P) Base Score: 5.4
    Note: the CVSS base Score for this issue could be 4.3 or lower, and
	it could be higher than 5.4.
    Date Resolved: Stable (4.2.8p2) 07 Apr 2015
    Summary: An attacker knowing that NTP hosts A and B are peering with
	each other (symmetric association) can send a packet to host A
	with source address of B which will set the NTP state variables
	on A to the values sent by the attacker. Host A will then send
	on its next poll to B a packet with originate timestamp that
	doesn't match the transmit timestamp of B and the packet will
	be dropped. If the attacker does this periodically for both
	hosts, they won't be able to synchronize to each other. This is
	a known denial-of-service attack, described at
	https://www.eecis.udel.edu/~mills/onwire.html .

	According to the document the NTP authentication is supposed to
	protect symmetric associations against this attack, but that
	doesn't seem to be the case. The state variables are updated even
	when authentication fails and the peers are sending packets with
	originate timestamps that don't match the transmit timestamps on
	the receiving side.

	This seems to be a very old problem, dating back to at least
	xntp3.3wy. It's also in the NTPv3 (RFC 1305) and NTPv4 (RFC 5905)
	specifications, so other NTP implementations with support for
	symmetric associations and authentication may be vulnerable too.
	An update to the NTP RFC to correct this error is in-process.
    Mitigation:
        Upgrade to 4.2.8p2, or later, from the NTP Project Download Page
	or the NTP Public Services Project Download Page
        Note that for users of autokey, this specific style of MITM attack
	is simply a long-known potential problem.
        Configure ntpd with appropriate time sources and monitor ntpd.
	Alert your staff if problems are detected. 
    Credit: This issue was discovered by Miroslav Lichvar, of Red Hat. 

* New script: update-leap
The update-leap script will verify and if necessary, update the
leap-second definition file.
It requires the following commands in order to work:

	wget logger tr sed shasum

Some may choose to run this from cron.  It needs more portability testing.

Bug Fixes and Improvements:

* [Bug 1787] DCF77's formerly "antenna" bit is "call bit" since 2003.
* [Bug 1960] setsockopt IPV6_MULTICAST_IF: Invalid argument.
* [Bug 2346] "graceful termination" signals do not do peer cleanup.
* [Bug 2728] See if C99-style structure initialization works.
* [Bug 2747] Upgrade libevent to 2.1.5-beta.
* [Bug 2749] ntp/lib/NTP/Util.pm needs update for ntpq -w, IPv6, .POOL. .
* [Bug 2751] jitter.h has stale copies of l_fp macros.
* [Bug 2756] ntpd hangs in startup with gcc 3.3.5 on ARM.
* [Bug 2757] Quiet compiler warnings.
* [Bug 2759] Expose nonvolatile/clk_wander_threshold to ntpq.
* [Bug 2763] Allow different thresholds for forward and backward steps.
* [Bug 2766] ntp-keygen output files should not be world-readable.
* [Bug 2767] ntp-keygen -M should symlink to ntp.keys.
* [Bug 2771] nonvolatile value is documented in wrong units.
* [Bug 2773] Early leap announcement from Palisade/Thunderbolt
* [Bug 2774] Unreasonably verbose printout - leap pending/warning
* [Bug 2775] ntp-keygen.c fails to compile under Windows.
* [Bug 2777] Fixed loops and decoding of Meinberg GPS satellite info.
  Removed non-ASCII characters from some copyright comments.
  Removed trailing whitespace.
  Updated definitions for Meinberg clocks from current Meinberg header files.
  Now use C99 fixed-width types and avoid non-ASCII characters in comments.
  Account for updated definitions pulled from Meinberg header files.
  Updated comments on Meinberg GPS receivers which are not only called GPS16x.
  Replaced some constant numbers by defines from ntp_calendar.h
  Modified creation of parse-specific variables for Meinberg devices
  in gps16x_message().
  Reworked mk_utcinfo() to avoid printing of ambiguous leap second dates.
  Modified mbg_tm_str() which now expexts an additional parameter controlling
  if the time status shall be printed.
* [Sec 2779] ntpd accepts unauthenticated packets with symmetric key crypto.
* [Sec 2781] Authentication doesn't protect symmetric associations against
  DoS attacks.
* [Bug 2783] Quiet autoconf warnings about missing AC_LANG_SOURCE.
* [Bug 2789] Quiet compiler warnings from libevent.
* [Bug 2790] If ntpd sets the Windows MM timer highest resolution
  pause briefly before measuring system clock precision to yield
  correct results.
* Comment from Juergen Perlinger in ntp_calendar.c to make the code clearer.
* Use predefined function types for parse driver functions
  used to set up function pointers.
  Account for changed prototype of parse_inp_fnc_t functions.
  Cast parse conversion results to appropriate types to avoid
  compiler warnings.
  Let ioctl() for Windows accept a (void *) to avoid compiler warnings
  when called with pointers to different types.

---
NTP 4.2.8p1 (Harlan Stenn <stenn@ntp.org>, 2015/02/04) 

Focus: Security and Bug fixes, enhancements.

Severity: HIGH
 
In addition to bug fixes and enhancements, this release fixes the
following high-severity vulnerabilities:

* vallen is not validated in several places in ntp_crypto.c, leading
  to a potential information leak or possibly a crash

    References: Sec 2671 / CVE-2014-9297 / VU#852879
    Affects: All NTP4 releases before 4.2.8p1 that are running autokey.
    CVSS: (AV:N/AC:L/Au:N/C:P/I:P/A:P) Base Score: 7.5
    Date Resolved: Stable (4.2.8p1) 04 Feb 2015
    Summary: The vallen packet value is not validated in several code
             paths in ntp_crypto.c which can lead to information leakage
	     or perhaps a crash of the ntpd process.
    Mitigation - any of:
	Upgrade to 4.2.8p1, or later, from the NTP Project Download Page
		or the NTP Public Services Project Download Page.
	Disable Autokey Authentication by removing, or commenting out,
		all configuration directives beginning with the "crypto"
		keyword in your ntp.conf file. 
    Credit: This vulnerability was discovered by Stephen Roettger of the
    	Google Security Team, with additional cases found by Sebastian
	Krahmer of the SUSE Security Team and Harlan Stenn of Network
	Time Foundation. 

* ::1 can be spoofed on some OSes, so ACLs based on IPv6 ::1 addresses
  can be bypassed.

    References: Sec 2672 / CVE-2014-9298 / VU#852879
    Affects: All NTP4 releases before 4.2.8p1, under at least some
	versions of MacOS and Linux. *BSD has not been seen to be vulnerable.
    CVSS: (AV:N/AC:L/Au:N/C:P/I:P/A:C) Base Score: 9
    Date Resolved: Stable (4.2.8p1) 04 Feb 2014
    Summary: While available kernels will prevent 127.0.0.1 addresses
	from "appearing" on non-localhost IPv4 interfaces, some kernels
	do not offer the same protection for ::1 source addresses on
	IPv6 interfaces. Since NTP's access control is based on source
	address and localhost addresses generally have no restrictions,
	an attacker can send malicious control and configuration packets
	by spoofing ::1 addresses from the outside. Note Well: This is
	not really a bug in NTP, it's a problem with some OSes. If you
	have one of these OSes where ::1 can be spoofed, ALL ::1 -based
	ACL restrictions on any application can be bypassed!
    Mitigation:
        Upgrade to 4.2.8p1, or later, from the NTP Project Download Page
	or the NTP Public Services Project Download Page
        Install firewall rules to block packets claiming to come from
	::1 from inappropriate network interfaces. 
    Credit: This vulnerability was discovered by Stephen Roettger of
	the Google Security Team. 

Additionally, over 30 bugfixes and improvements were made to the codebase.
See the ChangeLog for more information.

---
NTP 4.2.8 (Harlan Stenn <stenn@ntp.org>, 2014/12/18) 
 
Focus: Security and Bug fixes, enhancements.
 
Severity: HIGH
 
In addition to bug fixes and enhancements, this release fixes the
following high-severity vulnerabilities:

************************** vv NOTE WELL vv *****************************

The vulnerabilities listed below can be significantly mitigated by
following the BCP of putting

 restrict default ... noquery

in the ntp.conf file.  With the exception of:

   receive(): missing return on error
   References: Sec 2670 / CVE-2014-9296 / VU#852879

below (which is a limited-risk vulnerability), none of the recent
vulnerabilities listed below can be exploited if the source IP is
restricted from sending a 'query'-class packet by your ntp.conf file.

************************** ^^ NOTE WELL ^^ *****************************

* Weak default key in config_auth().

  References: [Sec 2665] / CVE-2014-9293 / VU#852879
  CVSS: (AV:N/AC:L/Au:M/C:P/I:P/A:C) Base Score: 7.3
  Vulnerable Versions: all releases prior to 4.2.7p11
  Date Resolved: 28 Jan 2010

  Summary: If no 'auth' key is set in the configuration file, ntpd
	would generate a random key on the fly.  There were two
	problems with this: 1) the generated key was 31 bits in size,
	and 2) it used the (now weak) ntp_random() function, which was
	seeded with a 32-bit value and could only provide 32 bits of
	entropy.  This was sufficient back in the late 1990s when the
	code was written.  Not today.

  Mitigation - any of:
	- Upgrade to 4.2.7p11 or later.
	- Follow BCP and put 'restrict ... noquery' in your ntp.conf file.

  Credit: This vulnerability was noticed in ntp-4.2.6 by Neel Mehta
  	of the Google Security Team.

* Non-cryptographic random number generator with weak seed used by
  ntp-keygen to generate symmetric keys.

  References: [Sec 2666] / CVE-2014-9294 / VU#852879
  CVSS: (AV:N/AC:L/Au:M/C:P/I:P/A:C) Base Score: 7.3
  Vulnerable Versions: All NTP4 releases before 4.2.7p230
  Date Resolved: Dev (4.2.7p230) 01 Nov 2011

  Summary: Prior to ntp-4.2.7p230 ntp-keygen used a weak seed to
  	prepare a random number generator that was of good quality back
	in the late 1990s. The random numbers produced was then used to
	generate symmetric keys. In ntp-4.2.8 we use a current-technology
	cryptographic random number generator, either RAND_bytes from
	OpenSSL, or arc4random(). 

  Mitigation - any of:
  	- Upgrade to 4.2.7p230 or later.
	- Follow BCP and put 'restrict ... noquery' in your ntp.conf file.

  Credit:  This vulnerability was discovered in ntp-4.2.6 by
  	Stephen Roettger of the Google Security Team.

* Buffer overflow in crypto_recv()

  References: Sec 2667 / CVE-2014-9295 / VU#852879
  CVSS: (AV:N/AC:L/Au:N/C:P/I:P/A:P) Base Score: 7.5
  Versions: All releases before 4.2.8
  Date Resolved: Stable (4.2.8) 18 Dec 2014

  Summary: When Autokey Authentication is enabled (i.e. the ntp.conf
  	file contains a 'crypto pw ...' directive) a remote attacker
	can send a carefully crafted packet that can overflow a stack
	buffer and potentially allow malicious code to be executed
	with the privilege level of the ntpd process.

  Mitigation - any of:
  	- Upgrade to 4.2.8, or later, or
	- Disable Autokey Authentication by removing, or commenting out,
	  all configuration directives beginning with the crypto keyword
	  in your ntp.conf file. 

  Credit: This vulnerability was discovered by Stephen Roettger of the
  	Google Security Team. 

* Buffer overflow in ctl_putdata()

  References: Sec 2668 / CVE-2014-9295 / VU#852879
  CVSS: (AV:N/AC:L/Au:N/C:P/I:P/A:P) Base Score: 7.5
  Versions: All NTP4 releases before 4.2.8
  Date Resolved: Stable (4.2.8) 18 Dec 2014

  Summary: A remote attacker can send a carefully crafted packet that
  	can overflow a stack buffer and potentially allow malicious
	code to be executed with the privilege level of the ntpd process.

  Mitigation - any of:
  	- Upgrade to 4.2.8, or later.
	- Follow BCP and put 'restrict ... noquery' in your ntp.conf file.

  Credit: This vulnerability was discovered by Stephen Roettger of the
  	Google Security Team. 

* Buffer overflow in configure()

  References: Sec 2669 / CVE-2014-9295 / VU#852879
  CVSS: (AV:N/AC:L/Au:N/C:P/I:P/A:P) Base Score: 7.5
  Versions: All NTP4 releases before 4.2.8
  Date Resolved: Stable (4.2.8) 18 Dec 2014

  Summary: A remote attacker can send a carefully crafted packet that
	can overflow a stack buffer and potentially allow malicious
	code to be executed with the privilege level of the ntpd process.

  Mitigation - any of:
  	- Upgrade to 4.2.8, or later.
	- Follow BCP and put 'restrict ... noquery' in your ntp.conf file.

  Credit: This vulnerability was discovered by Stephen Roettger of the
	Google Security Team. 

* receive(): missing return on error

  References: Sec 2670 / CVE-2014-9296 / VU#852879
  CVSS: (AV:N/AC:L/Au:N/C:N/I:N/A:P) Base Score: 5.0
  Versions: All NTP4 releases before 4.2.8
  Date Resolved: Stable (4.2.8) 18 Dec 2014

  Summary: Code in ntp_proto.c:receive() was missing a 'return;' in
  	the code path where an error was detected, which meant
	processing did not stop when a specific rare error occurred.
	We haven't found a way for this bug to affect system integrity.
	If there is no way to affect system integrity the base CVSS
	score for this bug is 0. If there is one avenue through which
	system integrity can be partially affected, the base score
	becomes a 5. If system integrity can be partially affected
	via all three integrity metrics, the CVSS base score become 7.5.

  Mitigation - any of:
        - Upgrade to 4.2.8, or later,
        - Remove or comment out all configuration directives
	  beginning with the crypto keyword in your ntp.conf file. 

  Credit: This vulnerability was discovered by Stephen Roettger of the
  	Google Security Team. 

See http://support.ntp.org/security for more information.

New features / changes in this release:

Important Changes

* Internal NTP Era counters

The internal counters that track the "era" (range of years) we are in
rolls over every 136 years'.  The current "era" started at the stroke of
midnight on 1 Jan 1900, and ends just before the stroke of midnight on
1 Jan 2036.
In the past, we have used the "midpoint" of the  range to decide which
era we were in.  Given the longevity of some products, it became clear
that it would be more functional to "look back" less, and "look forward"
more.  We now compile a timestamp into the ntpd executable and when we
get a timestamp we us the "built-on" to tell us what era we are in.
This check "looks back" 10 years, and "looks forward" 126 years.

* ntpdc responses disabled by default

Dave Hart writes:

For a long time, ntpq and its mostly text-based mode 6 (control) 
protocol have been preferred over ntpdc and its mode 7 (private 
request) protocol for runtime queries and configuration.  There has 
been a goal of deprecating ntpdc, previously held back by numerous 
capabilities exposed by ntpdc with no ntpq equivalent.  I have been 
adding commands to ntpq to cover these cases, and I believe I've 
covered them all, though I've not compared command-by-command 
recently. 

As I've said previously, the binary mode 7 protocol involves a lot of 
hand-rolled structure layout and byte-swapping code in both ntpd and 
ntpdc which is hard to get right.  As ntpd grows and changes, the 
changes are difficult to expose via ntpdc while maintaining forward 
and backward compatibility between ntpdc and ntpd.  In contrast, 
ntpq's text-based, label=value approach involves more code reuse and 
allows compatible changes without extra work in most cases. 

Mode 7 has always been defined as vendor/implementation-specific while 
mode 6 is described in RFC 1305 and intended to be open to interoperate 
with other implementations.  There is an early draft of an updated 
mode 6 description that likely will join the other NTPv4 RFCs 
eventually. (http://tools.ietf.org/html/draft-odonoghue-ntpv4-control-01)

For these reasons, ntpd 4.2.7p230 by default disables processing of 
ntpdc queries, reducing ntpd's attack surface and functionally 
deprecating ntpdc.  If you are in the habit of using ntpdc for certain 
operations, please try the ntpq equivalent.  If there's no equivalent, 
please open a bug report at http://bugs.ntp.org./

In addition to the above, over 1100 issues have been resolved between
the 4.2.6 branch and 4.2.8.  The ChangeLog file in the distribution
lists these.

--- 
NTP 4.2.6p5 (Harlan Stenn <stenn@ntp.org>, 2011/12/24) 
 
Focus: Bug fixes
 
Severity: Medium 
 
This is a recommended upgrade. 

This release updates sys_rootdisp and sys_jitter calculations to match the
RFC specification, fixes a potential IPv6 address matching error for the
"nic" and "interface" configuration directives, suppresses the creation of
extraneous ephemeral associations for certain broadcastclient and
multicastclient configurations, cleans up some ntpq display issues, and
includes improvements to orphan mode, minor bugs fixes and code clean-ups.

New features / changes in this release:

ntpd

 * Updated "nic" and "interface" IPv6 address handling to prevent 
   mismatches with localhost [::1] and wildcard [::] which resulted from
   using the address/prefix format (e.g. fe80::/64)
 * Fix orphan mode stratum incorrectly counting to infinity
 * Orphan parent selection metric updated to includes missing ntohl()
 * Non-printable stratum 16 refid no longer sent to ntp
 * Duplicate ephemeral associations suppressed for broadcastclient and
   multicastclient without broadcastdelay
 * Exclude undetermined sys_refid from use in loopback TEST12
 * Exclude MODE_SERVER responses from KoD rate limiting
 * Include root delay in clock_update() sys_rootdisp calculations
 * get_systime() updated to exclude sys_residual offset (which only
   affected bits "below" sys_tick, the precision threshold)
 * sys.peer jitter weighting corrected in sys_jitter calculation

ntpq

 * -n option extended to include the billboard "server" column
 * IPv6 addresses in the local column truncated to prevent overruns

--- 
NTP 4.2.6p4 (Harlan Stenn <stenn@ntp.org>, 2011/09/22) 
 
Focus: Bug fixes and portability improvements 
 
Severity: Medium 
 
This is a recommended upgrade. 
 
This release includes build infrastructure updates, code 
clean-ups, minor bug fixes, fixes for a number of minor 
ref-clock issues, and documentation revisions. 
 
Portability improvements affect AIX, HP-UX, Linux, OS X and 64-bit time_t. 
 
New features / changes in this release: 
 
Build system 
 
* Fix checking for struct rtattr 
* Update config.guess and config.sub for AIX 
* Upgrade required version of autogen and libopts for building 
  from our source code repository 
 
ntpd 
 
* Back-ported several fixes for Coverity warnings from ntp-dev 
* Fix a rare boundary condition in UNLINK_EXPR_SLIST() 
* Allow "logconfig =allall" configuration directive 
* Bind tentative IPv6 addresses on Linux 
* Correct WWVB/Spectracom driver to timestamp CR instead of LF 
* Improved tally bit handling to prevent incorrect ntpq peer status reports 
* Exclude the Undisciplined Local Clock and ACTS drivers from the initial 
  candidate list unless they are designated a "prefer peer" 
* Prevent the consideration of Undisciplined Local Clock or ACTS drivers for 
  selection during the 'tos orphanwait' period 
* Prefer an Orphan Mode Parent over the Undisciplined Local Clock or ACTS 
  drivers 
* Improved support of the Parse Refclock trusttime flag in Meinberg mode 
* Back-port utility routines from ntp-dev: mprintf(), emalloc_zero() 
* Added the NTPD_TICKADJ_PPM environment variable for specifying baseline 
  clock slew on Microsoft Windows 
* Code cleanup in libntpq 
 
ntpdc 
 
* Fix timerstats reporting 
 
ntpdate 
 
* Reduce time required to set clock 
* Allow a timeout greater than 2 seconds 
 
sntp 
 
* Backward incompatible command-line option change: 
  -l/--filelog changed -l/--logfile (to be consistent with ntpd) 
 
Documentation 
 
* Update html2man. Fix some tags in the .html files 
* Distribute ntp-wait.html 

---
NTP 4.2.6p3 (Harlan Stenn <stenn@ntp.org>, 2011/01/03)

Focus: Bug fixes and portability improvements

Severity: Medium

This is a recommended upgrade.

This release includes build infrastructure updates, code
clean-ups, minor bug fixes, fixes for a number of minor
ref-clock issues, and documentation revisions.

Portability improvements in this release affect AIX, Atari FreeMiNT,
FreeBSD4, Linux and Microsoft Windows.

New features / changes in this release:

Build system
* Use lsb_release to get information about Linux distributions.
* 'test' is in /usr/bin (instead of /bin) on some systems.
* Basic sanity checks for the ChangeLog file.
* Source certain build files with ./filename for systems without . in PATH.
* IRIX portability fix.
* Use a single copy of the "libopts" code.
* autogen/libopts upgrade.
* configure.ac m4 quoting cleanup.

ntpd
* Do not bind to IN6_IFF_ANYCAST addresses.
* Log the reason for exiting under Windows.
* Multicast fixes for Windows.
* Interpolation fixes for Windows.
* IPv4 and IPv6 Multicast fixes.
* Manycast solicitation fixes and general repairs.
* JJY refclock cleanup.
* NMEA refclock improvements.
* Oncore debug message cleanup.
* Palisade refclock now builds under Linux.
* Give RAWDCF more baud rates.
* Support Truetime Satellite clocks under Windows.
* Support Arbiter 1093C Satellite clocks under Windows.
* Make sure that the "filegen" configuration command defaults to "enable".
* Range-check the status codes (plus other cleanup) in the RIPE-NCC driver.
* Prohibit 'includefile' directive in remote configuration command.
* Fix 'nic' interface bindings.
* Fix the way we link with openssl if openssl is installed in the base
  system.

ntp-keygen
* Fix -V coredump.
* OpenSSL version display cleanup.

ntpdc
* Many counters should be treated as unsigned.

ntpdate
* Do not ignore replies with equal receive and transmit timestamps.

ntpq
* libntpq warning cleanup.

ntpsnmpd
* Correct SNMP type for "precision" and "resolution".
* Update the MIB from the draft version to RFC-5907.

sntp
* Display timezone offset when showing time for sntp in the local
  timezone.
* Pay proper attention to RATE KoD packets.
* Fix a miscalculation of the offset.
* Properly parse empty lines in the key file.
* Logging cleanup.
* Use tv_usec correctly in set_time().
* Documentation cleanup.

---
NTP 4.2.6p2 (Harlan Stenn <stenn@ntp.org>, 2010/07/08)

Focus: Bug fixes and portability improvements

Severity: Medium

This is a recommended upgrade.

This release includes build infrastructure updates, code
clean-ups, minor bug fixes, fixes for a number of minor
ref-clock issues, improved KOD handling, OpenSSL related
updates and documentation revisions.

Portability improvements in this release affect Irix, Linux,
Mac OS, Microsoft Windows, OpenBSD and QNX6

New features / changes in this release:

ntpd
* Range syntax for the trustedkey configuration directive
* Unified IPv4 and IPv6 restrict lists

ntpdate
* Rate limiting and KOD handling

ntpsnmpd
* default connection to net-snmpd via a unix-domain socket
* command-line 'socket name' option

ntpq / ntpdc
* support for the "passwd ..." syntax
* key-type specific password prompts

sntp
* MD5 authentication of an ntpd
* Broadcast and crypto
* OpenSSL support

---
NTP 4.2.6p1 (Harlan Stenn <stenn@ntp.org>, 2010/04/09)

Focus: Bug fixes, portability fixes, and documentation improvements

Severity: Medium

This is a recommended upgrade.

---
NTP 4.2.6 (Harlan Stenn <stenn@ntp.org>, 2009/12/08)

Focus: enhancements and bug fixes.

---
NTP 4.2.4p8 (Harlan Stenn <stenn@ntp.org>, 2009/12/08)

Focus: Security Fixes

Severity: HIGH

This release fixes the following high-severity vulnerability:

* [Sec 1331] DoS with mode 7 packets - CVE-2009-3563.

  See http://support.ntp.org/security for more information.

  NTP mode 7 (MODE_PRIVATE) is used by the ntpdc query and control utility.
  In contrast, ntpq uses NTP mode 6 (MODE_CONTROL), while routine NTP time
  transfers use modes 1 through 5.  Upon receipt of an incorrect mode 7
  request or a mode 7 error response from an address which is not listed
  in a "restrict ... noquery" or "restrict ... ignore" statement, ntpd will
  reply with a mode 7 error response (and log a message).  In this case:

	* If an attacker spoofs the source address of ntpd host A in a
	  mode 7 response packet sent to ntpd host B, both A and B will
	  continuously send each other error responses, for as long as
	  those packets get through.

	* If an attacker spoofs an address of ntpd host A in a mode 7
	  response packet sent to ntpd host A, A will respond to itself
	  endlessly, consuming CPU and logging excessively.

  Credit for finding this vulnerability goes to Robin Park and Dmitri
  Vinokurov of Alcatel-Lucent.

THIS IS A STRONGLY RECOMMENDED UPGRADE.

---
ntpd now syncs to refclocks right away.

Backward-Incompatible changes:

ntpd no longer accepts '-v name' or '-V name' to define internal variables.
Use '--var name' or '--dvar name' instead. (Bug 817)

---
NTP 4.2.4p7 (Harlan Stenn <stenn@ntp.org>, 2009/05/04)

Focus: Security and Bug Fixes

Severity: HIGH

This release fixes the following high-severity vulnerability:

* [Sec 1151] Remote exploit if autokey is enabled.  CVE-2009-1252

  See http://support.ntp.org/security for more information.

  If autokey is enabled (if ntp.conf contains a "crypto pw whatever"
  line) then a carefully crafted packet sent to the machine will cause
  a buffer overflow and possible execution of injected code, running
  with the privileges of the ntpd process (often root).

  Credit for finding this vulnerability goes to Chris Ries of CMU.

This release fixes the following low-severity vulnerabilities:

* [Sec 1144] limited (two byte) buffer overflow in ntpq.  CVE-2009-0159
  Credit for finding this vulnerability goes to Geoff Keating of Apple.
  
* [Sec 1149] use SO_EXCLUSIVEADDRUSE on Windows
  Credit for finding this issue goes to Dave Hart.

This release fixes a number of bugs and adds some improvements:

* Improved logging
* Fix many compiler warnings
* Many fixes and improvements for Windows
* Adds support for AIX 6.1
* Resolves some issues under MacOS X and Solaris

THIS IS A STRONGLY RECOMMENDED UPGRADE.

---
NTP 4.2.4p6 (Harlan Stenn <stenn@ntp.org>, 2009/01/07)

Focus: Security Fix

Severity: Low

This release fixes oCERT.org's CVE-2009-0021, a vulnerability affecting
the OpenSSL library relating to the incorrect checking of the return
value of EVP_VerifyFinal function.

Credit for finding this issue goes to the Google Security Team for
finding the original issue with OpenSSL, and to ocert.org for finding
the problem in NTP and telling us about it.

This is a recommended upgrade.
---
NTP 4.2.4p5 (Harlan Stenn <stenn@ntp.org>, 2008/08/17)

Focus: Minor Bugfixes 

This release fixes a number of Windows-specific ntpd bugs and 
platform-independent ntpdate bugs. A logging bugfix has been applied
to the ONCORE driver.

The "dynamic" keyword and is now obsolete and deferred binding to local 
interfaces is the new default. The minimum time restriction for the 
interface update interval has been dropped. 

A number of minor build system and documentation fixes are included. 

This is a recommended upgrade for Windows. 

---
NTP 4.2.4p4 (Harlan Stenn <stenn@ntp.org>, 2007/09/10)

Focus: Minor Bugfixes

This release updates certain copyright information, fixes several display
bugs in ntpdc, avoids SIGIO interrupting malloc(), cleans up file descriptor
shutdown in the parse refclock driver, removes some lint from the code,
stops accessing certain buffers immediately after they were freed, fixes
a problem with non-command-line specification of -6, and allows the loopback
interface to share addresses with other interfaces.

---
NTP 4.2.4p3 (Harlan Stenn <stenn@ntp.org>, 2007/06/29)

Focus: Minor Bugfixes

This release fixes a bug in Windows that made it difficult to
terminate ntpd under windows.
This is a recommended upgrade for Windows.

---
NTP 4.2.4p2 (Harlan Stenn <stenn@ntp.org>, 2007/06/19)

Focus: Minor Bugfixes

This release fixes a multicast mode authentication problem, 
an error in NTP packet handling on Windows that could lead to 
ntpd crashing, and several other minor bugs. Handling of 
multicast interfaces and logging configuration were improved. 
The required versions of autogen and libopts were incremented.
This is a recommended upgrade for Windows and multicast users.

---
NTP 4.2.4 (Harlan Stenn <stenn@ntp.org>, 2006/12/31)

Focus: enhancements and bug fixes.

Dynamic interface rescanning was added to simplify the use of ntpd in 
conjunction with DHCP. GNU AutoGen is used for its command-line options 
processing. Separate PPS devices are supported for PARSE refclocks, MD5 
signatures are now provided for the release files. Drivers have been 
added for some new ref-clocks and have been removed for some older 
ref-clocks. This release also includes other improvements, documentation 
and bug fixes. 

K&R C is no longer supported as of NTP-4.2.4. We are now aiming for ANSI 
C support.

---
NTP 4.2.0 (Harlan Stenn <stenn@ntp.org>, 2003/10/15)

Focus: enhancements and bug fixes.