Unspecified vulnerability in Cisco IOS 12.0 through 12.4 allows remote attackers to execute arbitrary code via a malformed SIP packet, aka CSCsi80749.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5075
http://www.vupen.com/english/advisories/2007/2816
http://www.securityfocus.com/bid/25239
http://www.cisco.com/en/US/products/products_security_advisory09186a0080899653.shtml
http://securitytracker.com/id?1018533