Woffice Core <= 5.4.21 - Cross-Site Request Forgery to User Registration Approval

The Woffice Core plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 5.4.21. This is due to missing or incorrect nonce validation on the 'woffice_handle_user_approval_actions' function. This makes it possible for unauthenticated attackers to approve registration for any user via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.