The Autonomic Networking Infrastructure (ANI) implementation in Cisco IOS 12.2 12.4 15.0 15.2 15.3 and 15.4 and IOS XE 3.10.xS through 3.13.xS before 3.13.1S allows remote attackers to cause a denial of service (disrupted domain access) via spoofed AN messages that reset a finite state machine aka Bug ID CSCup62293.