The Session Initiation Protocol (SIP) implementation in multiple Cisco products including IP Phone models 7940 and 7960, IOS versions in the 12.2 train, and Secure PIX 5.2.9 to 6.2.2 allows remote attackers to cause a denial of service and possibly execute arbitrary code via crafted INVITE messages, as demonstrated by the OUSPG PROTOS c07-sip test suite.
https://exchange.xforce.ibmcloud.com/vulnerabilities/11379
http://www.securitytracker.com/id?1006145
http://www.securitytracker.com/id?1006144
http://www.securitytracker.com/id?1006143
http://www.securityfocus.com/bid/6904
http://www.kb.cert.org/vuls/id/528719
http://www.cisco.com/warp/public/707/cisco-sa-20030221-protos.shtml