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 spoof Autonomic Networking Registration Authority (ANRA) responses, and consequently bypass intended device and node access restrictions or cause a denial of service (disrupted domain access), via crafted AN messages, aka Bug ID CSCup62191.