Cisco Adaptive Security Appliance (ASA) Software 8.4 before 8.4(7.2) 8.7 before 8.7(1.8) 9.0 before 9.0(3.6) and 9.1 before 9.1(2.8) allows remote attackers to cause a denial of service (firewall-session disruption or device reload) via crafted ICMP packets aka Bug ID CSCui77398.