Cisco Unified Presence Server (CUPS) 8.6, 9.0, and 9.1 before 9.1.1 allows remote attackers to cause a denial of service (CPU consumption) via crafted packets to the SIP TCP port, aka Bug ID CSCua89930.
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130227-cups