The Call To Action Plugin plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 3.1.3. This is due to missing nonce validation in the cbox_options_page() function which handles saving, creating, and deleting plugin settings. The form rendered on the settings page does not include a wp_nonce_field(), and the save handler does not call wp_verify_nonce() or check_admin_referer() before processing settings updates via $wpdb->update(). This makes it possible for unauthenticated attackers to modify plugin settings such as call-to-action box title, content, link URL, image URL, colors, and other configuration options via a forged request, granted they can trick a site administrator into performing an action such as clicking on a link.