Cisco Security Advisory – Cisco Unified Communications Manager, formerly Cisco Unified CallManager, contains two denial of service (DoS) vulnerabilities in the Session Initiation Protocol (SIP) service. An exploit of these vulnerabilities may cause an interruption in voice services. Cisco will release free software updates that address these vulnerabilities and this advisory will be updated as fixed software becomes available. There are no workarounds for these vulnerabilities.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/70284/cisco-sa-20080924-cucm.txt
Source: https://packetstormsecurity.com/files/70284/Cisco-Security-Advisory-20080924-cucm.html