The Advanced Contact form 7 DB WordPress plugin before 1.8.7 does not have authorisation nor CSRF checks in the acf7_db_edit_scr_file_delete AJAX action and does not validate the file to be deleted allowing any authenticated user to delete arbitrary files on the web server. For example removing the wp-config.php allows attackers to trigger WordPress setup again gain administrator privileges and execute arbitrary code or display arbitrary content to the users.