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.