The Stop Spammers Classic plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2026.1. This is due to missing nonce validation in the ss_addtoallowlist class. This makes it possible for unauthenticated attackers to add arbitrary email addresses to the spam allowlist via a forged request granted they can trick a site administrator into performing an action such as clicking on a link. The vulnerability was partially patched in version 2026.1.

The Anti-Spam: Spam Protection | Block Spam Users, Comments, Forms plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2024.7. This is due to missing or incorrect nonce validation in the 'ss_option_maint.php' and 'ss_user_filter_list' files. This makes it possible for unauthenticated attackers to delete pending comments, and re-enable a previously blocked user via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

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.