-----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 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 . 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 chunk 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-p2, 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 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.2 (FreeBSD) iD8DBQE/S5yPFdaIBMps37IRAlrjAJwPNdxh0GeZQUVk7WYHHefQ6qAnGgCfRi9B 7p9xVP++yIsd0W4UXnKde2k= =aFZp -----END PGP SIGNATURE-----