Cisco ASA Software Internet Key Exchange Version 1 XAUTH Denial of Service Vulnerability

A vulnerability in the Internet Key Exchange Version 1 (IKEv1) XAUTH code of Cisco ASA Software could allow an authenticated, remote attacker to cause a reload of an affected system.

The vulnerability is due to insufficient validation of the IKEv1 XAUTH parameters passed during an IKEv1 negotiation. An attacker could exploit this vulnerability by sending crafted parameters.

Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability only affects systems configured in routed firewall mode and in single or multiple context mode. This vulnerability can be triggered by IPv4 or IPv6 traffic. A valid IKEv1 Phase 1 needs to be established to exploit this vulnerability, which means that an attacker would need to have knowledge of a pre-shared key or have a valid certificate for phase 1 authentication.

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://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170419-asa-xauth [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170419-asa-xauth”]