The Master Addons for Elementor WordPress plugin before 3.1.9 does not perform an authorization check on the AJAX action that deactivates its Popup Builder popups, relying only on a nonce that is publicly output to every visitor, allowing unauthenticated attackers to permanently disable any popup on the site.
https://wpscan.com/vulnerability/e052c684-7b82-4555-8bf7-600b894264db/