The IGMPv3 implementation in Cisco IOS 12.2, 12.3, 12.4, and 15.0 and IOS XE 2.5.x before 2.5.2, when PIM is enabled, allows remote attackers to cause a denial of service (device reload) via a malformed IGMP packet, aka Bug ID CSCte14603.
http://www.cisco.com/en/US/products/products_security_advisory09186a0080b4a310.shtml