PDF Invoices & Packing Slips for WooCommerce <= 5.14.0 - Insecure Direct Object Reference to Authenticated (Contributor+) Sensitive Information Disclosure via 'order_id' Shortcode Attribute

The PDF Invoices & Packing Slips for WooCommerce plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.14.0 via the generate_document_shortcode due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with contributor-level access and above, to mint publicly accessible, session-free download links for arbitrary third-party orders, exposing customer names, billing and shipping addresses, email addresses, phone numbers, order and invoice numbers, line items, totals, payment details, and customer notes contained in those orders' invoices and packing slips. Exploitation requires the plugin's Document link access type setting to be configured to 'full'; with the default 'logged_in' value, generated URLs are signed with a per-session nonce rather than the order_key, making the shortcode path unexploitable for unauthorized access to third-party orders.