Cisco Security Advisory – Cisco Unified Communications Manager, which was formerly Cisco Unified CallManager, contains a denial of service (DoS) vulnerability in the Session Initiation Protocol (SIP) service. An exploit of this vulnerability may cause an interruption in voice services.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/81592/cisco-sa-20090923-cm.txt
Source: https://packetstormsecurity.com/files/81592/Cisco-Security-Advisory-20090923-cm.html