FreeBSD Security Advisories
2013-Feb-19 14:03 UTC
FreeBSD Security Advisory FreeBSD-SA-13:01.bind
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ============================================================================FreeBSD-SA-13:01.bind Security Advisory The FreeBSD Project Topic: BIND remote DoS with deliberately crafted DNS64 query Category: contrib Module: bind Announced: 2013-02-19 Affects: FreeBSD 9.x and later Corrected: 2013-01-08 09:05:09 UTC (stable/9, 9.1-STABLE) 2013-02-19 13:27:20 UTC (releng/9.0, 9.0-RELEASE-p6) 2013-02-19 13:27:20 UTC (releng/9.1, 9.1-RELEASE-p1) CVE Name: CVE-2012-5688 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:http://security.FreeBSD.org/>. I. Background BIND 9 is an implementation of the Domain Name System (DNS) protocols. The named(8) daemon is an Internet Domain Name Server. DNS64 is an IPv6 transition mechanism that will return a synthesized AAAA response even if there is only an A record available. II. Problem Description Due to a software defect a crafted query can cause named(8) to crash with an assertion failure. III. Impact If named(8) is configured to use DNS64, an attacker who can send it a query can cause named(8) to crash, resulting in a denial of service. IV. Workaround No workaround is available, but systems not configured to use DNS64 using the "dns64" configuration statement are not vulnerable. DNS64 is not enabled in the default configuration on FreeBSD. V. Solution Perform one of the following: 1) Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. Restart the named(8) daemon, or reboot your system. 2) To update your vulnerable system via a source code patch: The following patches have been verified to apply to the applicable FreeBSD release branches. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. # fetch http://security.FreeBSD.org/patches/SA-13:01/bind.patch # fetch http://security.FreeBSD.org/patches/SA-13:01/bind.patch.asc # gpg --verify bind.patch.asc b) Execute the following commands as root: # cd /usr/src # patch < /path/to/patch Recompile the operating system using buildworld and installworld as described in <URL:http://www.FreeBSD.org/handbook/makeworld.html>. Restart the named(8) daemon, or reboot your system. 3) To update your vulnerable system via a binary patch: Systems running a RELEASE version of FreeBSD on the i386 or amd64 platforms can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install Restart the named(8) daemon, or reboot your system. 4) Alternatively, 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 are not affected by this vulnerability: bind98-9.8.4.1 bind99-9.9.2.1 VI. Correction details The following list contains the revision numbers of each file that was corrected in FreeBSD. Branch/path Revision - ------------------------------------------------------------------------- stable/9/ r245163 releng/9.0/ r246989 releng/9.1/ r246989 - ------------------------------------------------------------------------- VII. References https://kb.isc.org/article/AA-00828 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2012-5688 The latest revision of this advisory is available at http://security.FreeBSD.org/advisories/FreeBSD-SA-13:01.bind.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (FreeBSD) iEYEARECAAYFAlEjf8MACgkQFdaIBMps37JUigCeIvjGL59H2froSeFqfPvlzM7L XpAAni7nW5GZt4AE3eSDQwE4ivCne6SK =Rxq4 -----END PGP SIGNATURE-----