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.