Cisco IOS 12.2 through 12.4 and 15.0 through 15.1, Cisco IOS XE 2.5.x and 2.6.x before 2.6.1, and Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 6.x before 6.1(5)SU1, 7.x before 7.1(5), and 8.0 before 8.0(2) allow remote attackers to cause a denial of service (device reload or voice-services outage) via crafted SIP registration traffic over UDP, aka Bug IDs CSCtf72678 and CSCtf14987.