Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2015.2302 BIND remote denial of service vulnerability 3 September 2015 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: bind Publisher: FreeBSD Operating System: FreeBSD Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2015-5986 CVE-2015-5722 Reference: ESB-2015.2301 ESB-2015.2300 Original Bulletin: https://security.FreeBSD.org/advisories/FreeBSD-SA-15:23.bind.asc - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-15:23.bind Security Advisory The FreeBSD Project Topic: BIND remote denial of service vulnerability Category: contrib Module: bind Announced: 2015-09-02 Credits: ISC Affects: FreeBSD 9.x Corrected: 2015-09-02 20:06:46 UTC (stable/9, 9.3-STABLE) 2015-09-02 20:07:03 UTC (releng/9.3, 9.3-RELEASE-p25) CVE Name: CVE-2015-5722 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. The libdns library is a library of DNS protocol support functions. II. Problem Description Parsing a malformed DNSSEC key can cause a validating resolver to exit due to a failed assertion in buffer.c. III. Impact A remote attacker can deliberately trigger the failed assertion which will cause an affected server to terminate, by using a query that requires a response from a zone containing a malformed key, resulting in a denial of service condition. Recursive servers are at greatest risk, however, an authoritative server could also be affected, if an attacker controls a zone that the server must query against to perform its zone service. 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-15:23/bind.patch # fetch https://security.FreeBSD.org/patches/SA-15:23/bind.patch.asc # gpg --verify bind.patch.asc Please note that FreeBSD 9.3-STABLE is also affected by another issue (CVE-2015-5986), and a different patch should be used. 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(8) daemon, or reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - - ------------------------------------------------------------------------- stable/9/ r287409 releng/9.3/ r287410 - - ------------------------------------------------------------------------- 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-01287> <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-5722> CVE-2015-5986 is listed here for completeness and affects FreeBSD 9.3-STABLE but not FreeBSD 9.3-RELEASE: <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-5986> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-15:23.bind.asc> - -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.1.7 (FreeBSD) iQIcBAEBCgAGBQJV52K9AAoJEO1n7NZdz2rnYQEP/1MY+pxPVMWT86qNKZ8upUpH LadLmtYAERrT9SMBrEFNCgylRdwNabTPKU0ZtxW8I57rks+j4bci053qo9Z7Hyo0 tbK3hTtxJZHNBO1G+NFfQxx9U+R+86Korx3NvDiB78XkJaab5On3dSgIMJYPEIL+ h0NEfYqe+X+LYg3W46faPdIuOsgxWSYN1T6mcZ5B5lucbT+LXjA5sRj+rUcE+a4O 2lIdM1oesWOZrEZo9FjK3UPvBbiEZkspr5IBd0zA825+BZNOpk06SOS/f3N0Pz8u S2vGlxcT37CzC9fPgjQpcNBmB+76xLgz74Inj4uPDSvCz+wmmcr95YOgheZb2N6K Bqakzy9TyRNk1aa8VXb8XpfyfMzroWG/vNjV6trI5wry7U0zRSl4dz+XAoz0A/eO 9ue88iWsVh97HBWKH94K8ZCA49G3NLgkbDkJ3awS4TfIKwwh9bGDiDepu1KMqnC1 EzyRk2fnr9JIreLj5zR1ctL1xGUvBIzWvHeT72PjgdZ/hqDoXTHKSVnDoR0c6T+U bJBJSLi3KUqaMkKRJez84r7G8RKtudLT292l4UQ3qgbiuaXagY6m1W0WBpLvw/zv RQOsG3HPpDrrV/LiSWKybEX2hIqIHd3tssfjQqvMa4WLO3h8wVONjw74YgRzZaYb t/1F4r4UYtfIJ7omydxx =B0u1 - -----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. NOTE: Third Party Rights 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. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 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 iQIVAwUBVee4uH6ZAP0PgtI9AQLr0hAAwzr1P43w8JYFNO9PpHZCRlpEGeLQl/yu IZtUWvcigg+fWGJTXKBtJWndNO/9pbj0cicPJgk1oa0e5S8gGO07WWwVLve9pCf8 juD8SXebPObRmlQYjvJyMTGnrukyL0IgKi5/6c4A/pmWgb3R7FxCBeFTLU43frAU tJEtkCHiZxc/BQl6zTLeNKsmqCsDvu1eKEB597a22IUua3mY1YRoS6mNjqv9R4wG cmebQ2WqXRZFJEC30ckGJVzRpAPDaf4FGgpALcAeCE1h5qTWgykXc8wjpZBv5a9n +At/Mf3hBfRR2n3qZSAS1l6C7B6aJEtEIRKUBL79BZJ0iBrd3UAbAwTj5qNihdSL jXrHhWKMp7udqKq9M2Qf/btaEPNTMSkr1V4pu8Q6X6oYZ5Wl+EcC9I0CBD/z+Cpv 6S6kxFZZXe7WxPlJpyuYLEkUPWfEs2FbzNpPC7lP/NFCXgJavZOT1inDGCv6P6TN As1SRVVV8KbM1pbzpruGR3IbgFaYvdHNeXghhziN91qZFIavsMcBU6FvWRrEoJ25 PNxxev67D9t3M3fmHZwnDEPfuW8RkbqM+qDhz5JzJ+Jp6KP9wYcJetGkAFiwtaJ8 fwfUiomk89yHiIKURwy0WgB15nhdVcXx9I6rX6kvZyUwDyZSt+nTDTptk8b7p3FN irn5pgUWjoQ= =R6g+ -----END PGP SIGNATURE-----