Siemens SCALANCE and RUGGEDCOM Devices (Update A)

An attacker with network access to the device could restart a critical network switch, interrupting communications to field devices and PLCs, or potentially run arbitrary code to manipulate network traffic or alter device configuration. This could disrupt process visibility, cause loss of control over remote assets, or enable further lateral movement into the control system network.

This vulnerability affects industrial network infrastructure across water utilities, power distribution, and manufacturing facilities that use Siemens SCALANCE or RUGGEDCOM switches. These switches are critical to connecting PLCs, RTUs, and other field devices. Any organization running the affected firmware versions should prioritize assessment and patching of their network backbone devices.

An attacker on the same network segment as the affected switch exploits a flaw in the STP (Spanning Tree Protocol) passive listening feature by sending specially crafted packets. The malformed packets trigger a reboot (denial of service) or, under specific network conditions, allow code execution on the switch. No authentication is required, and the attack does not require direct console access.