The PhastPress plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 3.10 This is due to the scripts service endpoint constructing its URL whitelist dynamically from the attacker-controlled HTTP 'Host' header. This makes it possible for unauthenticated attackers to spoof the header to match any target URL, bypassing the whitelist and forcing the server to make HTTP requests to arbitrary internal or external destinations and return the response content.