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.