The Web To Print Shop : uDraw WordPress plugin before 3.3.3 does not validate the url parameter in its udraw_convert_url_to_base64 AJAX action (available to both unauthenticated and authenticated users) before using it in the file_get_contents function and returning its content base64 encoded in the response. As a result, unauthenticated users could read arbitrary files on the web server (such as /etc/passwd, wp-config.php etc)