===================================================================== CERT-Renater Note d'Information No. 2011/VULN146 _____________________________________________________________________ DATE : 23/02/2011 HARDWARE PLATFORM(S) : / OPERATING SYSTEM(S) : Systems running Asterisk Open Source version 1.4.x, 1.6.x, Asterisk Business Edition version C.x.x, AsteriskNOW version 1.5, s800i version 1.2.x. ====================================================================== http://downloads.asterisk.org/pub/security/AST-2011-002.html ______________________________________________________________________ Asterisk Project Security Advisory - AST-2011-002 Product Asterisk Summary Multiple array overflow and crash vulnerabilities in UDPTL code Nature of Advisory Exploitable Stack and Heap Array Overflows Susceptibility Remote Unauthenticated Sessions Severity Critical Exploits Known No Reported On January 27, 2011 Reported By Matthew Nicholson Posted On February 21, 2011 Last Updated On February 21, 2011 Advisory Contact Matthew Nicholson CVE Name Description When decoding UDPTL packets, multiple stack and heap based arrays can be made to overflow by specially crafted packets. Systems doing T.38 pass through or termination are vulnerable. Resolution The UDPTL decoding routines have been modified to respect the limits of exploitable arrays. In asterisk versions not containing the fix for this issue, disabling T.38 support will prevent this vulnerability from being exploited. T.38 support can be disabled in chan_sip by setting the t38pt_udptl option to "no" (it is off by default). t38pt_udptl = no The chan_ooh323 module should also be disabled by adding the following line in modles.conf. noload => chan_ooh323 Affected Versions Product Release Series Asterisk Open Source 1.4.x All versions Asterisk Open Source 1.6.x All versions Asterisk Business Edition C.x.x All versions AsteriskNOW 1.5 All versions s800i (Asterisk Appliance) 1.2.x All versions Corrected In Product Release Asterisk Open Source 1.4.39.2, 1.6.1.22, 1.6.2.16.2, 1.8.2.4 Asterisk Business Edition C.3.6.3 Patches URL Branch http://downloads.asterisk.org/pub/security/AST-2011-002-1.4.diff 1.4 http://downloads.asterisk.org/pub/security/AST-2011-002-1.6.1.diff 1.6.1 http://downloads.asterisk.org/pub/security/AST-2011-002-1.6.2.diff 1.6.2 http://downloads.asterisk.org/pub/security/AST-2011-002-1.8.diff 1.8 Links Asterisk Project Security Advisories are posted at http://www.asterisk.org/security This document may be superseded by later versions; if so, the latest version will be posted at http://downloads.digium.com/pub/security/AST-2011-002.pdf and http://downloads.digium.com/pub/security/AST-2011-002.html Revision History Date Editor Revisions Made 02/21/11 Matthew Nicholson Initial Release Asterisk Project Security Advisory - AST-2011-002 Copyright (c) 2011 Digium, Inc. All Rights Reserved. Permission is hereby granted to distribute and publish this advisory in its original, unaltered form. ====================================================================== ========================================================= Les serveurs de référence du CERT-Renater http://www.urec.fr/securite http://www.cru.fr/securite http://www.renater.fr ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 23 - 25 Rue Daviel | fax : 01-53-94-20-41 + + 75013 Paris | email: certsvp@renater.fr + =========================================================