The TiendaCrypto para WooCommerce WordPress plugin through 1.2.1 does not correctly verify the authenticity of its payment webhook, validating the request signature against a key that is always empty, which allows unauthenticated attackers to forge webhook notifications and mark arbitrary WooCommerce orders as paid on web servers that preserve request header case.
https://wpscan.com/vulnerability/d19c174c-0032-4f5d-b9be-c4f690e4c8ca/