WP Fastest Cache <= 1.1.2 - Missing Authorization in 'wpfc_clear_cache_of_allsites_callback'

The WP Fastest Cache plugin for WordPress is vulnerable to unauthorized data deletion due to a missing capability check on the wpfc_clear_cache_of_allsites_callback function in versions up to, and including, 1.1.2. This makes it possible for authenticated attackers with subscriber-level access to delete caches.