STRABL <= 4.5 - Unauthenticated Arbitrary Webhook Creation via REST API Endpoint

Summary

The STRABL – A checkout solution plugin for WordPress is vulnerable to Missing Authentication in all versions up to and including 4.5. The plugin registers a REST API webhook endpoint at /wp-json/strabl/webhook/order with a permission_callback of __return_true, which allows all incoming requests without any authentication or authorization checks. No shared secret, signature validation, HMAC verification, or token-based authentication is implemented. This makes it possible for unauthenticated attackers to create fraudulent WooCommerce orders and mark them as completed by supplying paymentStatus=paid, manipulate existing order statuses by providing an externalOrderId, create new WordPress user accounts with the customer role, issue refunds on existing orders, cancel existing orders, and apply chargeback fees — all without making a legitimate payment or having any valid credentials.