Unspecified vulnerability in Cisco IOS 12.0 through 12.4, when configured with (1) IP Service Level Agreements (SLAs) Responder, (2) Session Initiation Protocol (SIP), (3) H.323 Annex E Call Signaling Transport, or (4) Media Gateway Control Protocol (MGCP) allows remote attackers to cause a denial of service (blocked input queue on the inbound interface) via a crafted UDP packet.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6720
https://exchange.xforce.ibmcloud.com/vulnerabilities/49419
http://www.securitytracker.com/id?1021904
http://www.securityfocus.com/bid/34245
http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90469.shtml
http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90426.shtml