The Protocol Independent Multicast (PIM) application in Cisco Adaptive Security Appliance (ASA) Software 9.2(0.0) 9.2(0.104) 9.2(3.1) 9.2(3.4) 9.3(1.105) 9.3(2.100) 9.4(0.115) 100.13(0.21) 100.13(20.3) 100.13(21.9) and 100.14(1.1) does not properly implement multicast-forwarding registration which allows remote attackers to cause a denial of service (forwarding outage) via a crafted multicast packet aka Bug ID CSCus74398.