fetchmail-SA-2005-01: security announcement Topic: remote code injection vulnerability in fetchmail Author: Matthias Andree Version: 1.01 Announced: 2005-07-21 Type: buffer overrun/stack corruption/code injection Impact: account or system compromise possible through malicious or compromised POP3 servers Danger: high: in sensitive configurations, a full system compromise is possible CVE Name: CAN-2005-2335 URL: http://fetchmail.berlios.de/fetchmail-SA-2005-01.txt http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=212762 http://www.vuxml.org/freebsd/3497d7be-2fef-45f4-8162-9063751b573a.html http://www.freebsd.org/cgi/query-pr.cgi?pr=83805 Thanks: Edward J. Shornock (located the bug in UIDL code) Miloslav Trmac (pointed out 6.2.5.1 was faulty) Ludwig Nussel (provided minimal fix) Affects: fetchmail version 6.2.5.1 (denial of service) fetchmail version 6.2.5 (code injection) fetchmail version 6.2.0 (code injection) (other versions have not been checked) Not affected: fetchmail 6.2.5.2 fetchmail 6.2.6-pre6 fetchmail 6.3.0 (not released yet) Older versions may not have THIS bug, but had been found to contain other security-relevant bugs. Corrected: 2005-07-22 01:37 UTC (SVN) - committed bugfix (r4157) 2005-07-22 fetchmail-patch-6.2.5.2 released 0. Release history 2005-07-20 1.00 - Initial announcement 2005-07-22 1.01 - Withdrew 6.2.5.1 and 6.2.6-pre5, the fix was buggy and susceptible to denial of service through single-byte read from 0 when either a Message-ID: header was empty or the UIDL response did not contain an URL. - Add Credits. - Add 6.2.5.1 failure details to sections 2 and 3 - Revise section 5 and B. 1. Background fetchmail is a software package to retrieve mail from remote POP2, POP3, IMAP, ETRN or ODMR servers and forward it to local SMTP, LMTP servers or message delivery agents. 2. Problem description The POP3 code in fetchmail-6.2.5 and older that deals with UIDs (from the UIDL) reads the responses returned by the POP3 server into fixed-size buffers allocated on the stack, without limiting the input length to the buffer size. A compromised or malicious POP3 server can thus overrun fetchmail's stack. This affects POP3 and all of its variants, for instance but not limited to APOP. In fetchmail-6.2.5.1, the attempted fix prevented code injection via POP3 UIDL, but introduced two possible NULL dereferences that can be exploited to mount a denial of service attack. 3. Impact In fetchmail-6.2.5 and older, very long UIDs can cause fetchmail to crash, or potentially make it execute code placed on the stack. In some configurations, fetchmail is run by the root user to download mail for multiple accounts. In fetchmail-6.2.5.1, a server that responds with UID lines containing only the article number but no UID (in violation of RFC-1939), or a message without Message-ID when no UIDL support is available, can crash fetchmail. 4. Workaround No reasonable workaround can be offered at this time. 5. Solution Upgrade your fetchmail package to version 6.2.5.2. This requires the download of the fetchmail-6.2.5.tar.gz tarball and the fetchmail-patch-6.2.5.2.gz from BerliOS: <http://developer.berlios.de/project/showfiles.php?group_id=1824> To use the patch: 1. download fetchmail-6.2.5.tar.gz (or retrieve the version you already had downloaded) and fetchmail-patch-6.2.5.2.tar.gz 2. unpack the tarball: gunzip -c fetchmail-6.2.5.tar.gz | tar xf - 3. unpack the patch: gunzip fetchmail-patch-6.2.5.2.gz 4. apply the patch: cd fetchmail-6.2.5 ; patch -p1 <../fetchmail-patch-6.2.5.2 5. now configure and build as usual - detailed instructions in the file named "INSTALL". A. References fetchmail home page: <http://fetchmail.berlios.de/> B. Copyright, License and Warranty (C) Copyright 2005 by Matthias Andree, <matthias.andree@gmx.de>. Some rights reserved. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs German License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/2.0/de/ or send a letter to Creative Commons; 559 Nathan Abbott Way; Stanford, California 94305; USA. THIS WORK IS PROVIDED FREE OF CHARGE AND WITHOUT ANY WARRANTIES. Use the information herein at your own risk. END OF fetchmail-SA-2005-01.txt
*** Bug 99789 has been marked as a duplicate of this bug. ***
net-mail please provide an updated ebuild.
fetchmail-6.2.5.2.ebuild in CVS, unstable for all arches, except x86.
Arches please test and mark stable.
stable on ppc64
sparc stable.
Stable on hppa
Stable on amd64.
Stable on ppc
Stable on alpha + ia64.
GLSA 200507-21 s390 don't forget to mark stable.
