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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2012.0704 BIND resolver DoS when using DNSSEC Validation 26 July 2012 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: BIND Publisher: NetBSD Operating System: NetBSD Impact/Access: Denial of Service -- Remote/Unauthenticated Provide Misleading Information -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2012-3817 Reference: ESB-2012.0701 Original Bulletin: http://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2012-004.txt.asc - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NetBSD Security Advisory 2012-004 ================================= Topic: BIND resolver DoS when using DNSSEC Validation Version: NetBSD-current: affected prior to 20120724 NetBSD 6 BETA: affected prior to 20120725 NetBSD 5.1: affected prior to 20120725 NetBSD 5.0: affected prior to 20120725 NetBSD 4.0.*: affected prior to 20120724 NetBSD 4.0: affected prior to 20120724 pkgsrc: net/bind96, net/bind97, net/bind98, net/bind99 packages prior to 20120724 Severity: Denial of Service Fixed: NetBSD-current: Jul 24th, 2012 NetBSD-5-1 branch: Jul 25th, 2012 NetBSD-5-0 branch: Jul 25th, 2012 NetBSD-5 branch: Jul 25th, 2012 NetBSD-4-0 branch: Jul 24th, 2012 NetBSD-4 branch: Jul 24th, 2012 pkgsrc net/bind96: bind-9.6.3.1.ESV.7pl2 pkgsrc net/bind97: bind-9.7.6pl2 pkgsrc net/bind98: bind-9.8.3pl2nb1 pkgsrc net/bind99: bind-9.9.1pl2 Please note that NetBSD releases prior to 4.0 are no longer supported. It is recommended that all users upgrade to a supported release. Abstract ======== High numbers of queries with DNSSEC validation enabled can cause a crash with an assertion failure in named, caused by using a "bad cache" data structure before it has been initialized. This vulnerability has been assigned CVE-2012-3817. Technical Details ================= BIND 9 stores a cache of query names that are known to be failing due to misconfigured name servers or a broken chain of trust. Under high query loads when DNSSEC validation is active, it is possible for a condition to arise in which data from this cache of failing queries could be used before it was fully initialized, triggering an assertion failure. DNSSEC validation is enabled by default in NetBSD 5 and newer. Solutions and Workarounds ========================= We suggest fixing this vulnerability by using the current equivalent net/bind9* pkgsrc package instead of the in-system bind until the entire system can be updated (eg to the next security/critical release, or a binary snapshot from http://nyftp.netbsd.org/pub/NetBSD-daily/ from past the fix date). In order to apply this fix from source code, you will need to update the directory src/dist/bind under NetBSD 4.* and 5.*, or the directory src/external/bsd/bind/dist under NetBSD 6.0_BETA and later, to a version from a date later than what is mentioned in the "Fixed" section. Thanks To ========= Thanks to the Internet Systems Consortium for reporting this vulnerability and providing fixed versions. Revision History ================ 2012-07-25 Initial release More Information ================ Advisories may be updated as new information becomes available. The most recent version of this advisory (PGP signed) can be found at http://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2012-004.txt.asc Information about NetBSD and NetBSD security can be found at http://www.NetBSD.org/ and http://www.NetBSD.org/Security/ . Copyright 2012, The NetBSD Foundation, Inc. All Rights Reserved. Redistribution permitted only in full, unmodified form. $NetBSD: NetBSD-SA2012-004.txt,v 1.1 2012/07/25 15:53:18 tonnerre Exp $ - -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQEBZ+AAoJEAZJc6xMSnBujZsP/2ghbfGLB8kCGvtew2Mryh5Q HQtDGN20ESoxj8ACEiL5tjvvyEMIlepMtFVqSYIWuL4VuElbsRXHfH/7edgexTw5 NqT5TuKHU1j5OkGB5ZDnJkOTs5LdEe2YuUXha9OGQje+MCngIDy8bMwaCGE7cyGQ +DTYxqLKvdo11GrXrTBvAPoHgQ7Y/6RsZtSgu92awnVYzBh5Pgi8AoQdDNeXXjhy 88QIxrLuoHXpC9Q4ypQN85gkPtvL7otkvTDmEloFrbGKji5RT3vJY6MyQ0aG6PCE BZvDOJotyHNcY4Rl7bFuYrVCc9v3uasTYFAeU94T8J9LGLHvaZIrCyJZJftwZT6y +pyOYG8bIqy036XrUx5dtkCfRKuEDKsxLp6bRsz+7B319js0v2kSjD7dphNMaaLA OK+4vBHZRKV74vwLMvn5h0A8AimFtjebSyazen071aPJgOK/stm6mhV1oJHogQbb NLRQm0vaVnpL8kvsm9fddt0ZjKMRTNIbcrIbrp1EOmKUEu/2qOF05rsyMFJKzDcX 2nnR5znJRWiMERliwHviujqeD59sjsNGw0kKZQj7YcYtbxXge4DlKqVM8klCTeKS TYxVRhv/nW3hVNlUqYJwDBBaWoSK4LXC2aLAUtkD0LuQEQ0TZNmldImZQRsAW/MK W4g0S1gJsl7stgvtWqlJ =Jbln - -----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 iQIVAwUBUBClU+4yVqjM2NGpAQLqpg//bqmb5KqRqz7QebDjJGcAcKzNpWZ46jXY ZQUYvJL2ZA4eSnjv6i8wGa/HnXk+U8Z7sFy5qwTPqoMFIoF9mJ3Wnm9BDwfHkQ+h KBYmc5ydIX1gqnRfm98AlhlG/P5Ss1hiJsuxbg3ObR16Q6QmRRc+cixA+YpbKh35 7xv9UMQUAn2FE+GcQq2ghcwnvlF+h4XYrSK04mG/WVViqzPYmGHJyjxdx81JIGYm zApk54479lkfQfR+XphekUMCru+uZhMuE11AO8Fo2wGqVrnXGi8mXK02M1KSqCwj Q6qD4lWXKfxZk2F+m8xjoVd3z7DDjGfb4Mg7oS9eDbYuGjf7Jz+b8Syh7VrrZyF+ 8eU4QzIy0ko6reWNUiUz1CI3ZGPObWdWqMRuaLmsSiRPLGQX/maZRi4FvFHWgzxx ylAutnXF4Of7+3Oq08c0BVNjvyF6tLXAs2wfoIrcP/H8bo4Mzr34YrzekWdxfuIx HVa6504eMYXFIi613ztGZU4Idu5FAlKsK+HgeRyLMXl8+WhfLPNZOCdEmw7FE6Pv i788d1zvZaPKPjdt6tcNe7t33quVhopmGYyLtHGHyiWzkfJivUpvK5PH4oIx8Abt zBTwiRugT3q8X0JOxwMEFkenLhhv1+vjyUjwCQKms/RaMt3WYdY3KLlj1/hr3nqx yKNxoJvv/tw= =ucCT -----END PGP SIGNATURE-----