DHL for WooCommerce < 4.0.1 - Unauthenticated Shipping Label Disclosure via Unprotected Uploads Directory

The DHL Shipping Germany for WooCommerce WordPress plugin before 4.0.1 does not protect its shipping-label storage directory with server-independent access control, relying only on an Apache .htaccess file, so on a web server that does not honor .htaccess (such as nginx) an unauthenticated visitor can download stored shipping labels (each containing a customer's name and postal address) by requesting predictable filenames.