The Alex User Counter plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 6.0. This is due to missing nonce validation on the alex_user_counter_function() function. This makes it possible for unauthenticated attackers to update the plugin settings via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
https://plugins.trac.wordpress.org/browser/user-counter/trunk/user-counter.php#L41
https://plugins.trac.wordpress.org/browser/user-counter/tags/6.0/user-counter.php#L41