PAN-OS: Denial-of-Service (DoS) Vulnerability in DNS Proxy

An improper handling of exceptional conditions vulnerability exists in the DNS proxy feature of Palo Alto Networks PAN-OS software that enables a meddler-in-the-middle (MITM) to send specifically crafted traffic to the firewall that causes the service to restart unexpectedly. Repeated attempts to send this request result in denial-of-service to all PAN-OS services by restarting the device in maintenance mode.

Work around:
Customers with a Threat Prevention subscription can block attack traffic related to this vulnerability by enabling Threat ID 92406 (Applications and Threats content update 8556).

To completely mitigate the risk of this issue, temporarily disable the DNS proxy feature until you are able to upgrade your PAN-OS software to a fixed version.