The WP STAGING Pro WordPress Backup Plugin plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 5.6.0. This is due to missing or incorrect nonce validation on the 'sub' parameter called from the WP STAGING WordPress Backup Plugin - Backup Duplicator & Migration plugin. This makes it possible for unauthenticated attackers to include any local files that end in '-settings.php' via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.