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-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2003.0599 -- FreeBSD-SA-03:11.sendmail sendmail DNS map problem 27 August 2003 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: sendmail 8.12.0 through 8.12.8 Publisher: FreeBSD Operating System: FreeBSD UNIX Impact: Denial of Service Execute Arbitrary Code/Commands Access Required: Remote CVE Names: CAN-2003-0688 - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ============================================================================= FreeBSD-SA-03:11.sendmail Security Advisory The FreeBSD Project Topic: sendmail DNS map problem Category: contrib Module: contrib_sendmail Announced: 2003-08-26 Credits: Oleg Bulyzhin <oleg@rinet.ru> Affects: 4.6-RELEASE (up to -p16), 4.7-RELEASE (up to -p13), 4.8-RELEASE (up to -p3), 5.0-RELEASE (up to -p11) 4-STABLE prior to Mar 29 19:33:18 2003 UTC Corrected: 2003-08-25 22:33:14 UTC (RELENG_5_0) 2003-08-25 22:35:23 UTC (RELENG_4_8) 2003-08-25 22:36:10 UTC (RELENG_4_7) 2003-08-25 22:38:53 UTC (RELENG_4_6) FreeBSD only: NO For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:http://www.freebsd.org/security/>. I. Background FreeBSD includes sendmail(8), a general purpose internetwork mail routing facility, as the default Mail Transfer Agent (MTA). II. Problem Description Some versions of sendmail (8.12.0 through 8.12.8) contain a programming error in the code that implements DNS maps. A malformed DNS reply packet may cause sendmail to call `free()' on an uninitialized pointer. NOTE: The default sendmail configuration in FreeBSD does not utilize DNS maps. III. Impact Calling `free()' on an uninitialized pointer may result in a sendmail child process crashing. It may also be possible for an attacker to somehow influence the value of the `uninitialized pointer' and cause an arbitrary memory trunk to be freed. This could further lead to some other exploitable vulnerability, although no such cases are known at this time. IV. Workaround Do not use DNS maps. V. Solution Do one of the following: 1) Upgrade your vulnerable system to 4-STABLE, 5.1-RELEASE, or to the RELENG_5_1, RELENG_4_8, or RELENG_4_7 security branch dated after the correction date (5.1-RELEASE-p11, 4.8-RELEASE-p4, or 4.7-RELEASE-p14, respectively). 2) To patch your present system: The following patch has been verified to apply to FreeBSD 5.0, 4.8, 4.7, and 4.6 systems. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-03:11/sendmail.patch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-03:11/sendmail.patch.asc b) Execute the following commands as root: # cd /usr/src # patch < /path/to/patch # cd /usr/src/lib/libsm # make obj && make depend && make # cd /usr/src/lib/libsmutil # make obj && make depend && make # cd /usr/src/usr.sbin/sendmail # make obj && make depend && make && make install c) Restart sendmail. Execute the following command as root. # /bin/sh /etc/rc.sendmail restart VI. Correction details The following list contains the revision numbers of each file that was corrected in FreeBSD. Path Revision Branch - - ------------------------------------------------------------------------- src/UPDATING RELENG_5_0 1.229.2.17 RELENG_4_8 1.73.2.80.2.6 RELENG_4_7 1.73.2.74.2.17 RELENG_4_6 1.73.2.68.2.45 src/sys/conf/newvers.sh RELENG_5_0 1.48.2.12 RELENG_4_8 1.44.2.29.2.5 RELENG_4_7 1.44.2.26.2.16 RELENG_4_6 1.44.2.23.2.34 src/contrib/sendmail/src/sm_resolve.c RELENG_5_0 1.1.1.4.2.1 RELENG_4_8 1.1.1.1.2.2.4.1 RELENG_4_7 1.1.1.1.2.2.2.1 RELENG_4_6 1.1.1.1.2.1.2.2 - - ------------------------------------------------------------------------- VII. References <URL:http://www.sendmail.org/dnsmap1.html> <URL:http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0688> - -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.2 (FreeBSD) iD8DBQE/S4xUFdaIBMps37IRAoJ4AJ9AiL4AMlSXz/thD2SuNkKSQsUZHgCeKbds qEb9Em5ElZZOEnIajwneKIg= =SjNG - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. 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Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBP0v+4yh9+71yA2DNAQEt1AP/frRM0UkLZQNC5dZCNJqx0X/VTZSy7OOX x+GC3GKV96VtKbYe4YlqPLA6x93rxMGxpnR1H1ZKH97p889QlwZqj3fVEbOMhM1N uWK+VqIzMrw4ALIwNsTKP/VvMOePS/45OZRlZD8JGJzvILq2G2Y71xgf0uZ75vQy DBM7cdPzH4A= =ixiw -----END PGP SIGNATURE-----