An insecure configuration of the appweb daemon of Palo Alto Networks PAN-OS 8.1 allows a remote unauthenticated user to send a specifically crafted request to the device that causes the appweb service to crash. Repeated attempts to send this request result in denial of service to all PAN-OS services by restarting the device and putting it into maintenance mode. This issue impacts all versions of PAN-OS 8.0, and PAN-OS 8.1 versions earlier than 8.1.16.