From a8f8447d3c96ded8b1b24cdccbaeedc1931f9d3e Mon Sep 17 00:00:00 2001 From: Matthias Andree Date: Tue, 3 Aug 2021 17:07:33 +0200 Subject: update fetchmail-SA-2021-01 and reference fetchmail-SA-2008-01/CVE-2008-2711 --- fetchmail-SA-2021-01.txt | 91 +++++++++++++++++++++++++++--------------------- 1 file changed, 51 insertions(+), 40 deletions(-) diff --git a/fetchmail-SA-2021-01.txt b/fetchmail-SA-2021-01.txt index 5f2563be..2a5ca262 100644 --- a/fetchmail-SA-2021-01.txt +++ b/fetchmail-SA-2021-01.txt @@ -6,27 +6,30 @@ fetchmail-SA-2021-01: DoS or information disclosure logging long messages Topics: fetchmail denial of service or information disclosure when logging long messages Author: Matthias Andree -Version: 1.1 -Announced: 2021-07-28 -Type: missing variable initialization can cause read from bad memory +Version: 1.2 +Announced: 2021-07-28 (original), 2021-08-03 (last update) +Type: missing variable initialization can cause read from bad memory locations -Impact: fetchmail logs random information, or segfaults and aborts, +Impact: fetchmail logs random information, or segfaults and aborts, stalling inbound mail Danger: low Acknowledgment: Christian Herdtweck, Intra2net AG, Tübingen, Germany for analysis and report and a patch suggestion -CVE Name: CVE-2021-36386 +CVE Name: CVE-2021-36386 and CVE-2008-2711 URL: https://www.fetchmail.info/fetchmail-SA-2021-01.txt +URL: https://www.fetchmail.info/fetchmail-SA-2008-01.txt Project URL: https://www.fetchmail.info/ -Affects: - fetchmail releases up to and including 6.4.19 +Affects: - fetchmail releases up to and including 6.3.8 + - fetchmail releases 6.3.17 up to incl. 6.4.19 Not affected: - fetchmail releases 6.4.20 and newer + - fetchmail releases 6.3.9 to 6.3.16 Corrected in: c546c829 Git commit hash - 2021-07-28 fetchmail 6.4.20 release tarball + 2021-08-03 7.0.0-alpha9/6.5.0-beta4 snapshots 0. Release history @@ -35,6 +38,7 @@ Corrected in: c546c829 Git commit hash 2021-07-07 initial report to maintainer 2021-07-28 1.0 release 2021-07-28 1.1 update Git commit hash with correction +2021-08-03 1.2 add references to CVE-2008-2711/fetchmail-SA-2008-01 1. Background @@ -52,20 +56,27 @@ regular protocol ports. 2. Problem description and Impact ================================= -Fetchmail has long had support to assemble log/error messages that are -generated piecemeal, and takes care to reallocate the output buffer as needed. -In the reallocation case, i. e. when long log messages are assembled that can -stem from very long headers, and on systems that have a varargs.h/stdarg.h -interface (all modern systems), fetchmail's code would fail to reinitialize -the va_list argument to vsnprintf. - -The exact effects depend on the verbose mode (how many -v are given) of -fetchmail, computer architecture, compiler, operating system and -configuration. On some systems, the code just works without ill effects, some -systems log a garbage message (potentially disclosing sensitive information), -some systems log literally "(null)", some systems trigger SIGSEGV (signal +Fetchmail has long had support to assemble log/error messages that are +generated piecemeal, and takes care to reallocate the output buffer as needed. +In the reallocation case, i. e. when long log messages are assembled that can +stem from very long headers, and on systems that have a varargs.h/stdarg.h +interface (all modern systems), fetchmail's code would fail to reinitialize +the va_list argument to vsnprintf. + +The exact effects depend on the verbose mode (how many -v are given) of +fetchmail, computer architecture, compiler, operating system and +configuration. On some systems, the code just works without ill effects, some +systems log a garbage message (potentially disclosing sensitive information), +some systems log literally "(null)", some systems trigger SIGSEGV (signal #11), which crashes fetchmail, causing a denial of service on fetchmail's end. +The same bug then named CVE-2008-2711 had already been fixed in fetchmail 6.3.9, +but a code refactoring in fetchmail 6.3.17 (commit 414a3809 in 2010) +reintroduced the bug. +Fetchmail versions 6.4.19 and older are no longer supported, however. + +The bugfix used in 6.4.20 uses a different, more thorough, approach. + 3. Solution =========== @@ -75,15 +86,15 @@ Install fetchmail 6.4.20 or newer. The fetchmail source code is available from . -Distributors are encouraged to review the NEWS file and move forward to -6.4.20, rather than backport individual security fixes, because doing so -routinely misses other fixes crucial to fetchmail's proper operation, +Distributors are encouraged to review the NEWS file and move forward to +6.4.20, rather than backport individual security fixes, because doing so +routinely misses other fixes crucial to fetchmail's proper operation, for which no security announcements are issued, or documentation, or translation updates. -Fetchmail 6.4.X releases have been made with a focus on unchanged user and -program interfaces so as to avoid disruptions when upgrading from 6.3.Z or -6.4.X to 6.4.Y with Y > X. Care was taken to not change the interface +Fetchmail 6.4.X releases have been made with a focus on unchanged user and +program interfaces so as to avoid disruptions when upgrading from 6.3.Z or +6.4.X to 6.4.Y with Y > X. Care was taken to not change the interface incompatibly. @@ -93,8 +104,8 @@ A. Copyright, License and Non-Warranty (C) Copyright 2021 by Matthias Andree, . Some rights reserved. -fetchmail-SA-2021-01 © 2021 by Matthias Andree is licensed under CC -BY-ND 4.0. To view a copy of this license, visit +fetchmail-SA-2021-01 © 2021 by Matthias Andree is licensed under CC +BY-ND 4.0. To view a copy of this license, visit http://creativecommons.org/licenses/by-nd/4.0/ THIS WORK IS PROVIDED FREE OF CHARGE AND WITHOUT ANY WARRANTIES. @@ -103,17 +114,17 @@ Use the information herein at your own risk. END of fetchmail-SA-2021-01 -----BEGIN PGP SIGNATURE----- -iQIzBAEBCgAdFiEE3EplW9mTzUhx+oIQ5BKxVu/zhVoFAmEBxbQACgkQ5BKxVu/z -hVoESA/+JKX4wAG0v1+4+7yG8SsmWfWORnUzKLTVcjAu5osdQ1DamFgDEMqSd/ft -JswQdzMJfGSngKG+VgXPEu3l9jHyVWDwTWM7aKIo6VsRtJ6yBmBBQBQF5TSUARr7 -55Wm+GqNOQj4fp4xDvcswiMAbgpDZhtJEtWZhv96Uz6F+gjZ6qdufAYQlrPcH8AK -ByJTs9Alc9LqOgP0touXz+CMkJFjizsFBiB5YzrHjVlryojvVmrF858nt1AgeUFC -h8mWd9Y7qsJ+7OeF2BN5qre10LlJnEO3rZPz5OWcOYKCCuGka9nne9LjaouKLnY9 -8Yn4CqRMNhyj+5fXzNiXohJmjn2vZ/dgd/0mwNo5zyeC4z6J9KQuDS+/StGAyvLR -fHppSu8SNctw0EiEephZcDGd/rI6MzpfTwP7b1fy/TD3YcezMPNRRTTH2AxidbXh -/rSMVKWJ0tAucoEX3pR+6CVY8Eb0VZ09+iSqCmWe6Wsb9KN71K60FGVpnEq8BNWc -aRqk0JXugPxuiJIXQLIP8AnxMW/XJoJNDs37OkfFhNkkhRDjT7pmu7l+9eIIYiTI -cxpECB53pd6xlJb08KixDa2hu2UqjmfRe0KA//HaiUJy7RyGkxRbZ1GnMJHrCHCR -/YYyOJbe6yTMnWVI6Auva8WJNuHSZvdvKasAenDAHZy96mUj8FE= -=1rxO +iQIzBAEBCgAdFiEE3EplW9mTzUhx+oIQ5BKxVu/zhVoFAmEJW1kACgkQ5BKxVu/z +hVrcow//VOWtxFhC1H/BSUsyrx4n+vXJjpBxgu9uK/1RlA7//Bldh8y7X6XgfeBp +yEKwW71ecdLv4GAzDYoQ5ejrIWwjwkP4hOpFFrXBfv542qgUNIBXCJIkm8Ws4bF2 +IjWWfHqHrvQLaxdZ9R00GPr+3cKsc8OHjkq2tX23uBBgQ4xPn/Q6veBbm/Ok9lUn +Oge7ffn4eiHZ1d04sH/SyB6raEQuXyCAYVT1a2BBPiMUwsKBDj/LF7OtBrpRbdr9 +Sc1McL99w1lE85j1BI8xRFCmx+FuK2QQBfi1zst99b3IV+MYRC2vuowieMdzy37M +Wf6TtVWwWoZdxrRG0LIok43Kn4pklrFA67Wk4vCepxULOvlMPUsiCsv5TBJOdq2I +oLXpquSYz20BxyS3OxS2uu5WgD9IWMOJIn7ZoA8GqHLgSvClmD11njvQJq7bCUNu +SP6DC+WWbwoWM1oYZS2IHVccIh/rMvu2nptRz6adVASMebnY7rZCveN0YmcSXBUU +RbCW1cav1VO+BPvlV3AIX6VEjv7q9s839AieLTCkdar7LKf/ktKXQlNAtqbnPW5Q +O7ujhs+VvjlB7IfjhnoF77tu5NDtktTGgyW37XQPPLwpgpyvEyEWmzvB4hoxrWfV ++WNNfwmc6sUEs4hzgBmgtaX2exBvWscKk5xe5ks5ULRLJLZ9PnY= +=NnuJ -----END PGP SIGNATURE----- -- cgit v1.2.3