Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software WebVPN Portal Access Rule Bypass Vulnerability

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass a configured access rule and access parts of the WebVPN portal that are supposed to be blocked. The vulnerability is due to insufficient validation of URLs when portal access rules are configured. An attacker could exploit this vulnerability by accessing certain URLs on the affected device.