Denial of Service Vulnerability in SIMATIC CN 4100 by Siemens

CVE-2025-40939

What is CVE-2025-40939?

A vulnerability exists in the SIMATIC CN 4100 device, specifically affecting all versions prior to 4.0.1. This flaw arises from the presence of a USB port that permits unauthenticated connections. An attacker with physical access could exploit this weakness to forcibly reboot the device, potentially leading to a denial of service condition. It is crucial for users to ensure their systems are updated to mitigate this risk. For more details, visit the official Siemens security advisory.

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