CVE-2011-2665
reqresp_parser.c in the SIP channel driver in Asterisk Open Source 1.8.x before 1.8.4.3 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a SIP packet with a Contact header that lacks a < (less than) character. Date published : 2011-07-06 http://downloads.asterisk.org/pub/security/AST-2011-009-1.8.diff
http://downloads.asterisk.org/pub/security/AST-2011-009.html