The SMS Alert Order Notifications – WooCommerce plugin for WordPress is vulnerable to privilege escalation via account takeover in all versions up to, and including, 3.7.9. This is due to the plugin using the Host header to determine if the plugin is in a playground environment. This makes it possible for unauthenticated attackers to spoof the Host header to make the OTP code 1234 and authenticate as any user, including administrators.
A product requires authentication, but the product has an alternate path or channel that does not require authentication.