FreeBSD Security Advisory FreeBSD-SA-16:28.bind
10 October, 2016 by firstname.lastname@example.org | freebsd
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-16:28.bind Security Advisory The FreeBSD Project Topic: BIND remote Denial of Service vulnerability Category: contrib Module: bind Announced: 2016-10-10 Credits: ISC Affects: FreeBSD 9.x Corrected: 2016-09-28 06:11:01 UTC (stable/9, 9.3-STABLE) 2016-10-10 07:19:16 UTC (releng/9.3, 9.3-RELEASE-p48) CVE Name: CVE-2016-2776 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:https://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. II. Problem Description Testing by ISC has uncovered a critical error condition which can occur when a nameserver is constructing a response. A defect in the rendering of messages into packets can cause named to exit with an assertion failure in buffer.c while constructing a response to a query that meets certain criteria. This assertion can be triggered even if the apparent source address is not allowed to make queries (i.e. doesn't match 'allow-query'). [CVE-2016-2776] III. Impact A remote attacker who can send queries to a server running BIND can cause the server to crash, resulting in a Denial of Service condition. IV. Workaround No workaround is available, but hosts not running named(8) are not vulnerable. 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. The named service has to be restarted after the update. A reboot is recommended but not required. 2) 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 The named service has to be restarted after the update. A reboot is recommended but not required. 3) 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. [FreeBSD 9.3] # fetch https://security.FreeBSD.org/patches/SA-16:28/bind.patch # fetch https://security.FreeBSD.org/patches/SA-16:28/bind.patch.asc # gpg --verify bind.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile the operating system using buildworld and installworld as described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>. Restart the named service, or reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/9/ r306394 releng/9.3/ r306942 - ------------------------------------------------------------------------- To see which files were modified by a particular revision, run the following command, replacing NNNNNN with the revision number, on a machine with Subversion installed: # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base Or visit the following URL, replacing NNNNNN with the revision number: <URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN> VII. References <URL:https://kb.isc.org/article/AA-01419> <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-2776> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-16:28.bind.asc> -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.1.13 (FreeBSD) iQIcBAEBCgAGBQJX+0OlAAoJEO1n7NZdz2rnt/cQAJJ/P9/cNH4mB3Oq9kks1TJI thye1Bmd6BAS16UYj+S2POSkrwkTJLhg/Rtch/4O1TUJ7q86Dko/0nciF/4Qin/J LrNhX2TUUTpQygfWdzTqdk9EiHLKT46sNh1Two4Lb9gMuBulES9Fy40gj8y81ypv uys05i6DMAlY/EsmidTHFKUGGC9160XLS7wFWnlw9XglDHn2+pIDALHl77mmoXwR VKiCbGO6IybDV5bATh12eflCSb+IJRT0MMOwJAt3Nhzp//7t2tf+izazzfs43IH4 HRkiDfkkxqAMus6h0Dm4xR91oe/oSzlEedKFM3ctHfQqyIi+AP0FKixf8pS72n7o M0W5vIbkMSuTsiOTzyQUJpQ3tExvWeZjhNZj9U5trs2YNdPCRaM3pETUdF6GZmNC tnPiTZFst3ARsy/4oJg8Eeo/cyrd/sfPm4fXCbXkakL7ml/Mu+/KEyq5qw43FIXn 96/btRfHsPSpy74KRtLsqSM29eCK9puGhJIk1iBtuhuTvze/48Od7U5zWOjn8XiS o4oOyCtm3nQfB8VIzfypFAIUFFOqfHmsfP3s51J9tUXjxvORO3UWD3/R2wXLre2Y Z5+s7IUhesunZztGtaUFCqG28KCrzmSiIVXGRd/IsQCuTJ4DNiUFZofKYdI0B7fE hrSETFwDg/OYusZ5/96D =v9vM -----END PGP SIGNATURE----- _______________________________________________ email@example.com mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-announce To unsubscribe, send any mail to "firstname.lastname@example.org"