The Contests by Rewards Fuel plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.0.62. This is due to missing or incorrect nonce validation on the ajax_handler() function. This makes it possible for unauthenticated attackers to update the plugin's settings and inject malicious JavaScript via a forged request granted they can trick a site's user with the edit_posts capability into performing an action such as clicking on a link.