Symptom:
A vulnerability in the Internet Key Exchange version 1 (IKEv1) of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition.

The vulnerability is due to an improper validation of specific IKEv1 packets. An attacker could exploit this
vulnerability by sending crafted IKEv1 packets during an IKE negotiation. An exploit could allow the attacker
to cause the affected device to reload, resulting in a DoS condition.

Cisco has released software updates that address this vulnerability. There are no workarounds that address
this vulnerability.

This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-ike-dos

Conditions:
See Affected Products Section of the Advisory. 

To determine whether a release is affected by any published Cisco Security Advisory, use the Cisco IOS Software Checker on Cisco.com at the following link: https://tools.cisco.com/security/center/softwarechecker.x