The Master Elements WordPress plugin through 8.0 does not validate and escape the meta_ids parameter of its remove_post_meta_condition AJAX action (available to both unauthenticated and authenticated users) before using it in a SQL statement, leading to an unauthenticated SQL Injection
https://wpscan.com/vulnerability/a72bf075-fd4b-4aa5-b4a4-5f62a0620643