Memory leak in Cisco IOS 12.2, 15.1, and 15.2; IOS XE 3.4.2S through 3.4.5S; and IOS XE 3.6.xS before 3.6.1S allows remote attackers to cause a denial of service (memory consumption or device reload) via malformed IKEv1 packets, aka Bug ID CSCtx66011.