The Sell Media plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.5.5. This is due to missing or incorrect nonce validation on the sell_media_process() function. This makes it possible for unauthenticated attackers to sell media paypal orders via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
CWE-352