chan_iax2.c in the IAX2 channel driver in Asterisk Open Source 1.4.x before 1.4.41.1, 1.6.2.x before 1.6.2.18.1, and 1.8.x before 1.8.4.3, and Asterisk Business Edition C.3 before C.3.7.3, accesses a memory address contained in an option control frame, which allows remote attackers to cause a denial of service (daemon crash) or possibly have unspecified other impact via a crafted frame.
https://exchange.xforce.ibmcloud.com/vulnerabilities/68205
http://www.securityfocus.com/bid/48431
http://www.debian.org/security/2011/dsa-2276
http://securitytracker.com/id?1025708
http://secunia.com/advisories/45239
http://secunia.com/advisories/45201
http://secunia.com/advisories/45048
http://secunia.com/advisories/44973
http://lists.fedoraproject.org/pipermail/package-announce/2011-July/062628.html
http://downloads.asterisk.org/pub/security/AST-2011-010.html
http://downloads.asterisk.org/pub/security/AST-2011-010-1.8.diff