The SNMP Trap Agent service in Cisco Unified Communications Manager (CUCM) 4.1 before 4.1(3)SR6, 4.2 before 4.2(3)SR3, 4.3 before 4.3(2), 5.x before 5.1(3), and 6.x before 6.1(1) allows remote attackers to cause a denial of service (core dump and service restart) via a series of malformed UDP packets, as demonstrated by the IP Stack Integrity Checker (ISIC), aka Bug ID CSCsj24113.