PDF Invoices & Packing Slips for WooCommerce < 3.8.1 - Unauthenticated Server-Side Request Forgery

Description

The PDF Invoices & Packing Slips for WooCommerce plugin for WordPress is vulnerable to Server-Side Request Forgery in versions up to, and including, 3.8.0 via the transform() function. This can allow unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.