Apache Httpd < 2.0.55 : SSLVerifyClient bypass

A flaw in the mod_ssl handling of the “SSLVerifyClient” directive. This flaw would occur if a virtual host has been configured using “SSLVerifyClient optional” and further a directive “SSLVerifyClient required” is set for a specific location. For servers configured in this fashion, an attacker may be able to access resources that should otherwise be protected, by not supplying a client certificate when connecting.