The GPRS Tunneling Protocol (GTP) inspection engine in Cisco ASA Software 8.2 before 8.2(5.51), 8.4 before 8.4(7.15), 8.7 before 8.7(1.13), 9.0 before 9.0(4.8), and 9.1 before 9.1(5.1) allows remote attackers to cause a denial of service (device reload) via a crafted series of GTP packets, aka Bug ID CSCum56399.