The Cache Purger < 2.3.21 - Missing Authorization to Authenticated (Subscriber+) Arbitrary Log Deletion via 'the_log_purge' Parameter

Description

The The Cache Purger plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 2.3.20. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to permanently truncate the plugin's cache-purge audit log (wp-content/purge.log), destroying the entire cache-purge audit history. The tcp_log_purge nonce is rendered in the admin bar on frontend pages accessible to all authenticated users including subscribers, meaning any authenticated user possesses the nonce required to trigger the deletion.