Payment Gateway for PayPal on WooCommerce vulnerabilities

The Payment Gateway for PayPal on WooCommerce WordPress plugin before 9.2.1 does not verify that an incoming payment notification was confirmed in the store's configured payment environment or paid to the store's own merchant account before marking an order complete. This allows unauthenticated users to mark their own orders as paid using a genuine transaction from a payment sandbox they control.

The Payment Gateway for PayPal on WooCommerce plugin up to version 9.1.4 contains an unauthenticated Broken Access Control vulnerability. An unauthenticated attacker can bypass authorization mechanisms and gain unauthorized access to functions or data.

The Payment Gateway for PayPal on WooCommerce WordPress plugin before 9.2.1 does not verify that payment actually succeeded before completing an order in its PayPal return handler: it reads attacker-controlled parameters, performs no amount comparison and no order-ownership check, and completes the order even when the server-side gateway verification fails, allowing an unauthenticated attacker to mark arbitrary orders as paid without paying.