The plugin contains a missing authentication flaw in the REST API webhook endpoint "/wp-json/strabl/webhook/order". The endpoint uses a `permission callback` set to ` return true`, allowing all requests to bypass authentication and authorization checks. Because there is no shared secret, signature validation, HMAC verification, or token-based authentication, unauthenticated users can perform several unauthorized actions. These include creating fraudulent WooCommerce orders and marking them as completed by setting the `paymentStatus` variable to `paid`, manipulating order statuses via the `externalOrderId` variable, creating new WordPress user accounts with the customer role, issuing refunds, cancelling orders, and applying chargeback fees.