The Layer 4 Redirect (L4R) feature in Cisco IOS XE 2.x and 3.x before 3.10.4S, 3.11 before 3.11.3S, 3.12 before 3.12.2S, 3.13 before 3.13.1S, 3.14 before 3.14.0S, and 3.15 before 3.15.0S allows remote attackers to cause a denial of service (device reload) via malformed (1) IPv4 or (2) IPv6 packets, aka Bug ID CSCuq59131.