Cisco VPN Client Denial of Service Vulnerability

Cisco VPN Client contains a vulnerability that could allow an authenticated, local attacker to cause a denial of service (DoS) condition on a targeted system.

The vulnerability is due to improper interaction between the VPN driver and the operating system kernel on a device running the vulnerable software. A local attacker could exploit the vulnerability by running a crafted program designed to submit malicious input to the vulnerable system. Processing the malicious input could cause the host operating system to crash, resulting in a DoS condition.

Proof-of-concept code that exploits this vulnerability is publicly available.

Cisco has confirmed this vulnerability; however, software updates are not available.

As of July 30, 2012, Cisco VPN Client reached the End of Software Maintenance. Customers running the vulnerable software are advised to upgrade to Cisco AnyConnect Secure Mobility Client.