Cisco Security Advisory – A vulnerability in the Internet Key Exchange version 1 (IKEv1) fragmentation code of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to cause an exhaustion of available memory or a reload of the affected system. The vulnerability is due to the improper handling of crafted, fragmented IKEv1 packets. An attacker could exploit this vulnerability by sending crafted UDP packets to the affected system. An exploit could allow the attacker to cause a reload of the affected system. Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability can be triggered by IPv4 and IPv6 traffic. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.