The OPay Payment Gateway for WooCommerce WordPress plugin through 2.5.5 does not properly verify that payment notifications originate from the payment provider, as the secret used to validate their signature is empty by default, allowing unauthenticated attackers to forge a valid notification and mark arbitrary orders as paid, cancelled or failed.

The OPay Payment Gateway for WooCommerce WordPress plugin through 2.5.5 does not properly verify that payment notifications originate from the payment provider, as the secret used to validate their signature is empty by default, allowing unauthenticated attackers to forge a valid notification and mark arbitrary orders as paid, cancelled or failed.