The Stop Spammers Security | Block Spam Users, Comments, Forms plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2024.4. This is due to missing or incorrect nonce validation on the sfs_process AJAX action. This makes it possible for unauthenticated attackers to add arbitrary IPs to the plugin's allowlist and blocklist via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.