Fancy Product Designer | WooCommerce WordPress <= 6.4.8 - Unauthenticated Server-Side Request Forgery via Race Condition

The Fancy Product Designer plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 6.4.8. This is due to a time-of-check/time-of-use (TOCTOU) race condition in the 'url' parameter of the fpd_custom_uplod_file AJAX action. The plugin validates the URL by calling getimagesize() first, then later retrieves the same URL using file_get_contents(). This makes it possible for unauthenticated attackers to exploit the timing gap to perform SSRF attacks by serving a valid image during validation, then changing the response to redirect to arbitrary internal or external URLs during the actual fetch.