-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ============================================================================= FreeBSD-SA-11:06.bind Security Advisory The FreeBSD Project Topic: Remote packet Denial of Service against named(8) servers Category: contrib Module: bind Announced: 2011-12-23 Affects: All supported versions of FreeBSD. Corrected: 2011-11-17 01:10:16 UTC (RELENG_7, 7.4-STABLE) 2011-12-23 15:00:37 UTC (RELENG_7_4, 7.4-RELEASE-p5) 2011-12-23 15:00:37 UTC (RELENG_7_3, 7.3-RELEASE-p9) 2011-11-17 00:36:10 UTC (RELENG_8, 8.2-STABLE) 2011-12-23 15:00:37 UTC (RELENG_8_2, 8.2-RELEASE-p5) 2011-12-23 15:00:37 UTC (RELENG_8_1, 8.1-RELEASE-p7) 2011-12-01 21:13:41 UTC (RELENG_9, 9.0-STABLE) 2011-12-01 21:17:59 UTC (RELENG_9_0, 9.0-RC3) 2011-11-16 23:41:13 UTC (ports tree) CVE Name: CVE-2011-4313 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background BIND 9 is an implementation of the Domain Name System (DNS) protocols. The named(8) daemon is an Internet Domain Name Server. II. Problem Description A remote attacker could cause the BIND resolver to cache an invalid record, which could cause the BIND daemon to crash when that record is being queried. III. Impact An attacker that is able to send an specifically crafted response to the BIND daemon can cause it to crash, resulting in a denial of service. Note that due to the nature of this vulnerability, the attacker does not necessarily have to have query access to the victim server. The vulnerability can be triggered by tricking legitimate clients, for instance spam filtering systems or an end user browser, which can be made to the query on their behalf. IV. Workaround No workaround is available, but systems not running the BIND resolving name server are not affected. Servers that are running in authoritative-only mode appear not to be affected by this vulnerability. V. Solution Perform one of the following: 1) Upgrade your vulnerable system to 7-STABLE or 8-STABLE, or to the RELENG_8_2, RELENG_8_1, RELENG_7_4, or RELENG_7_3 security branch dated after the correction date. 2) To update your vulnerable system via a source code patch: The following patches have been verified to apply to FreeBSD 7.4, 7.3, 8.2 and 8.1 systems. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. [FreeBSD 7.3-RELEASE and 7.4-RELEASE] # fetch http://security.FreeBSD.org/patches/SA-11:06/bind7.patch # fetch http://security.FreeBSD.org/patches/SA-11:06/bind7.patch.asc [FreeBSD 8.1-RELEASE and 8.2-RELEASE] # fetch http://security.FreeBSD.org/patches/SA-11:06/bind8.patch # fetch http://security.FreeBSD.org/patches/SA-11:06/bind8.patch.asc b) Execute the following commands as root: # cd /usr/src # patch < /path/to/patch # cd /usr/src/lib/bind/ # make obj && make depend && make && make install # cd /usr/src/usr.sbin/named # make obj && make depend && make && make install 3) To update your vulnerable system via a binary patch: Systems running 7.4-RELEASE, 7.3-RELEASE, 8.2-RELEASE, or 8.1-RELEASE on the i386 or amd64 platforms can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install 4) Install and run BIND from the Ports Collection after the correction date. The following versions and newer versions of BIND installed from the Ports Collection already have the mitigation measure: bind96-9.6.3.1.ESV.R5.1 bind97-9.7.4.1 bind98-9.8.1.1 VI. Correction details The following list contains the revision numbers of each file that was corrected in FreeBSD. CVS: Branch Revision Path - ------------------------------------------------------------------------- RELENG_7 src/contrib/bind9/lib/dns/rbtdb.c 1.1.1.4.2.9 src/contrib/bind9/bin/named/query.c 1.1.1.6.2.8 RELENG_7_4 src/UPDATING 1.507.2.36.2.7 src/sys/conf/newvers.sh 1.72.2.18.2.10 src/contrib/bind9/lib/dns/rbtdb.c 1.1.1.4.2.6.2.1 src/contrib/bind9/bin/named/query.c 1.1.1.6.2.6.2.1 RELENG_7_3 src/UPDATING 1.507.2.34.2.11 src/sys/conf/newvers.sh 1.72.2.16.2.13 src/contrib/bind9/lib/dns/rbtdb.c 1.1.1.4.2.3.2.2 src/contrib/bind9/bin/named/query.c 1.1.1.6.2.3.2.2 RELENG_8 src/contrib/bind9/lib/dns/rbtdb.c 1.3.2.9 src/contrib/bind9/bin/named/query.c 1.3.2.8 RELENG_8_2 src/UPDATING 1.632.2.19.2.7 src/sys/conf/newvers.sh 1.83.2.12.2.10 src/contrib/bind9/lib/dns/rbtdb.c 1.3.2.5.2.1 src/contrib/bind9/bin/named/query.c 1.3.2.5.2.1 RELENG_8_1 src/UPDATING 1.632.2.14.2.10 src/sys/conf/newvers.sh 1.83.2.10.2.11 src/contrib/bind9/lib/dns/rbtdb.c 1.3.2.3.2.1 src/contrib/bind9/bin/named/query.c 1.3.2.3.2.1 RELENG_9 src/contrib/bind9/lib/dns/rbtdb.c 1.13.2.1 src/contrib/bind9/bin/named/query.c 1.11.2.1 RELENG_9_0 src/contrib/bind9/lib/dns/rbtdb.c 1.13.4.1 src/contrib/bind9/bin/named/query.c 1.11.4.1 - ------------------------------------------------------------------------- Subversion: Branch/path Revision - ------------------------------------------------------------------------- stable/7/ r227603 releng/7.4/ r228843 releng/7.3/ r228843 stable/8/ r227599 releng/8.2/ r228843 releng/8.1/ r228843 stable/9/ r228189 releng/9.0/ r228190 - ------------------------------------------------------------------------- VII. References https://www.isc.org/software/bind/advisories/cve-2011-4313 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-4313 The latest revision of this advisory is available at http://security.FreeBSD.org/advisories/FreeBSD-SA-11:06.bind.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) iEYEARECAAYFAk70nOoACgkQFdaIBMps37K18wCeLYPkREXJsMXYdzt+guRFcPZR VY4AoII3kmCzRX/gYRmPW7lwGqWIgwlM =wMSJ -----END PGP SIGNATURE-----