Cisco Adaptive Security Appliance Software Clientless SSL VPN Rewriter Denial of Service Vulnerability

A vulnerability in the clientless SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause an affected system to reload.

The vulnerability is due to a stack overflow while browsing internal resources via the clientless SSL VPN portal when the same-security-traffic permit intra-interface and management-access commands are configured. An attacker could exploit this vulnerability by accessing a crafted URL through the SSL VPN portal. An exploit could allow the attacker to reload the affected system and create a denial of service (DoS) condition.

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

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

Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.