The PeproDev WooCommerce Receipt Uploader WordPress plugin through 2.8.0 does not verify that a requested attachment belongs to the order referenced by its access token, allowing unauthenticated attackers to forge a token and disclose image attachments, including other customers' uploaded payment receipts, that they do not own.
https://wpscan.com/vulnerability/81ad791a-5a02-4207-9d06-9f17c45604a1/