Description
Your web server is configured to run as a proxy server. In order to avoid abuse, it's recommended to restrict access to this proxy server. Open proxy servers are dangerous both to your network and to the Internet at large.
Remediation
You can control who can access your proxy via the <Proxy> control block as in the following example:
<Proxy *> Order Deny,Allow Deny from all Allow from 192.168.0 </Proxy>