The Certificate Authority Proxy Function (CAPF) service in Cisco Unified Communications Manager 5.x before 5.1(3e) and 6.x before 6.1(3) allows remote attackers to cause a denial of service (voice service outage) by sending malformed input over a TCP session in which the "client terminates prematurely."
https://exchange.xforce.ibmcloud.com/vulnerabilities/48139
http://www.vupen.com/english/advisories/2009/0213
http://www.securitytracker.com/id?1021620
http://www.securityfocus.com/bid/33379
http://www.cisco.com/en/US/products/products_security_advisory09186a0080a61928.shtml