Cisco Security Advisory – Multiple vulnerabilities exist in the Session Initiation Protocol (SIP) implementation in Cisco IOS Software that could allow an unauthenticated, remote attacker to cause a reload of an affected device when SIP operation is enabled.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/94150/cisco-sa-20100922-sip.txt
Source: https://packetstormsecurity.com/files/94150/Cisco-Security-Advisory-20100922-sip.html