The Wp Social Login and Register Social Counter plugin for WordPress is vulnerable to missing authorization in versions up to, and including, 3.1.3. This is due to the REST routes wslu/v1/check_cache/{type}, wslu/v1/save_cache/{type}, and wslu/v1/settings/clear_counter_cache being registered with permission_callback set to __return_true and lacking capability or nonce validation in their handlers. This makes it possible for unauthenticated attackers to clear or overwrite the social counter cache via crafted REST requests.