The Easy Flashcards plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 0.1. This is due to missing or incorrect nonce validation on the 'ef_settings_submenu' page. This makes it possible for unauthenticated attackers to update settings and inject malicious web scripts via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.