Cisco Adaptive Security Appliance WebVPN Content Rewriter Denial of Service Vulnerability

A vulnerability in the WebVPN functionality of Cisco Adaptive Security Appliance (ASA) could allow an authenticated, remote attacker to cause an affected device to crash.

The vulnerability is due to a fault in the Proxy Bypass Content Rewriter implementation. An attacker could exploit this vulnerability by performing an HTTP request that triggers content rewriting. Depending on the configuration, a successful exploit could allow the attacker to cause the appliance to crash or trigger an error recovery event.

Cisco has confirmed the vulnerability in a security notice and released software updates.

To exploit this vulnerability, an attacker must authenticate to the targeted device. This access requirement reduces the likelihood of a successful exploit.