Cisco Security Advisory – Cisco Unified Communications Manager contains two denial of service (DoS) vulnerabilities that affect the processing of Session Initiation Protocol (SIP) messages. Exploitation of these vulnerabilities could cause an interruption of voice services.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/94153/cisco-sa-20100922-cucmsip.txt
Source: https://packetstormsecurity.com/files/94153/Cisco-Security-Advisory-20100922-cucmsip.html