The WordPress Contact Forms by Cimatti plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.9.2. This is due to missing or incorrect nonce validation on the process_bulk_action function. This makes it possible for unauthenticated attackers to delete forms via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
https://wordpress.org/plugins/contact-forms/#developers
https://plugins.trac.wordpress.org/changeset/3196728/
https://plugins.trac.wordpress.org/browser/contact-forms/trunk/accua-forms-submissions-page.php#L348
https://plugins.trac.wordpress.org/browser/contact-forms/trunk/accua-forms-list-page.php#L154