Trust Payments Gateway for WooCommerce < 3.1.0 - Unauthenticated Order Payment Completion via Payment Return Page

The Trust Payments Gateway for WooCommerce WordPress plugin before 3.1.0 does not verify the authenticity of the payment provider's response when a customer returns from the hosted payment page, nor bind that response to the targeted order or check the amount, allowing unauthenticated attackers to mark arbitrary orders as paid without any payment being made, and to retrieve order and customer details.