From: Harlan Stenn Date: Tue, 26 Apr 2016 23:24:25 +0000 (+0000) Subject: 4.2.8p7 documentation cleanup X-Git-Tag: NTP_4_2_8P7~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9347f68b2b6a0911261f6123e6c9a698598cdc01;p=thirdparty%2Fntp.git 4.2.8p7 documentation cleanup bk: 571ff8a98ACwWmZLDPGr0JOBZyTQHQ --- diff --git a/ChangeLog b/ChangeLog index 6dfbb4e80..29b9d2c4a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -5,9 +5,18 @@ time. Include passive servers in this check. HStenn. * [Sec 2945] Additional KoD packet checks. HStenn. * [Sec 2978] Interleave can be partially triggered. HStenn. +* [Sec 3007] Validate crypto-NAKs. Danny Mayer. * [Sec 3008] Always check the return value of ctl_getitem(). - initial work by HStenn - Additional cleanup of ctl_getitem by perlinger@ntp.org +* [Sec 3009] Crafted addpeer with hmode > 7 causes OOB error. perlinger@ntp.org + - added more stringent checks on packet content +* [Sec 3010] remote configuration trustedkey/requestkey values + are not properly validated. perlinger@ntp.org + - sidekick: Ignore keys that have an unsupported MAC algorithm + but are otherwise well-formed +* [Sec 3011] Duplicate IPs on unconfig directives will cause an assertion botch + - graciously accept the same IP multiple times. perlinger@ntp.org * [Sec 3020] Refclock impersonation. HStenn. * [Bug 2831] Segmentation Fault in DNS lookup during startup. perlinger@ntp.org - fixed yet another race condition in the threaded resolver code. @@ -21,15 +30,6 @@ * [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 3007] Validate crypto-NAKs. Danny Mayer. -* [Bug 3009] Crafted addpeer with hmode > 7 causes OOB error. perlinger@ntp.org - - added more stringent checks on packet content -* [Bug 3010] remote configuration trustedkey/requestkey values - are not properly validated. perlinger@ntp.org - - sidekick: Ignore keys that have an unsupported MAC algorithm - but are otherwise well-formed -* [Bug 3011] Duplicate IPs on unconfig directives will cause an assertion botch - - graciously accept the same IP multiple times. 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" diff --git a/NEWS b/NEWS index 91fa6a500..1edaf5dda 100644 --- a/NEWS +++ b/NEWS @@ -18,13 +18,14 @@ 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 +* 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: 2.6 - (AV:L/AC:H/Au:N/C:P/I:P/A:N) - CVSSv3: 4.0 - CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N + 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 @@ -37,17 +38,17 @@ following 9 low- and medium-severity vulnerabilities: Credit: This weakness was discovered independently by Loganaden Velvindron, and Matthew Van Gundy and Stephen Gray of Cisco ASIG. -* Clients that receive a KoD should validate the origin timestamp field. - References: Sec 2901 / CVE-2015-7704, CVE-2015-7705 +* 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 into 4.2.8p4 and 4.3.77. + 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: 4.3 - (AV:N/AC:M/Au:N/C:N/I:N/A:P) + 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: @@ -59,23 +60,43 @@ following 9 low- and medium-severity vulnerabilities: Monitor your ntpd instances. Credit: This problem was discovered by Michael Tatarinov. -* 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. - -* Zero origin timestamp bypass: Additional KoD checks. - References: Sec 2945 / 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. +* 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: 4.9 - (AV:N/AC:H/Au:S/C:N/I:N/A:C) - CVSSv3: 4.2 - CVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H + 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 @@ -97,6 +118,68 @@ following 9 low- and medium-severity vulnerabilities: 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 @@ -104,8 +187,8 @@ following 9 low- and medium-severity vulnerabilities: 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: 2.6 - (AV:N/AC:H/Au:N/C:N/I:P/A:N) - CVSSv3: 3.7 - CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N + 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 @@ -127,6 +210,19 @@ following 9 low- and medium-severity vulnerabilities: 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: @@ -134,8 +230,8 @@ for these are as follows: 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: 6.4 - (AV:N/AC:L/Au:N/C:N/I:P/A:P) - CVSSv3: 7.2 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L + 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 @@ -156,11 +252,12 @@ for these are as follows: 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 + 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: 3.5 - (AV:N/AC:M/Au:S/C:N/I:P/A:N) - CVSS3v: 5.3 - CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N + 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, @@ -182,21 +279,11 @@ Other fixes: * [Bug 2879] Improve NTP security against timing attacks. perlinger@ntp.org - integrated patches by Loganaden Velvidron with some modifications & unit tests -* [Bug 2952] Symmetric active/passive mode is broken. HStenn. * [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 3007] Validate crypto-NAKs. Danny Mayer. -* [Bug 3009] Crafted addpeer with hmode > 7 causes OOB error. perlinger@ntp.org - - added more stringent checks on packet content -* [Bug 3010] remote configuration trustedkey/requestkey values - are not properly validated. perlinger@ntp.org - - sidekick: Ignore keys that have an unsupported MAC algorithm - but are otherwise well-formed -* [Bug 3011] Duplicate IPs on unconfig directives will cause an assertion botch - - graciously accept the same IP multiple times. 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"