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."
The Certificate Authority Proxy Function (CAPF) service in Cisco Unified Communications Manager (CUCM) 4.1 before 4.1(3)SR7, 4.2 before 4.2(3)SR4, and 4.3 before 4.3(2) allows remote attackers to cause a denial of service (service crash) via malformed network traffic, aka Bug ID CSCsk46770.