Siemens SIMATIC Panels and WinCC (TIA Portal)
Specially crafted network packets sent to affected devices on port 4840/tcp
could allow an unauthenticated remote attacker to cause a denial of service
condition of the OPC communication or crash the device.

The security vulnerability could be exploited by an attacker with network
access to the affected systems. Successful exploitation requires no system
privileges and no user interaction. An attacker could use the vulnerability
to compromise availability of the OPC communication.