Attack Chain

1. Attacker identifies a vulnerable SIMATIC CN 4100 device exposed on the network.
2. Attacker establishes an unauthenticated connection to the device.
3. Attacker sends a high volume of requests to a resource-intensive endpoint.
4. The SIMATIC CN 4100 device attempts to process each request, consuming system resources.
5. The device’s CPU and memory resources become depleted due to the overwhelming number of requests.
6. Legitimate requests from authorized users are delayed or dropped.
7. The SIMATIC CN 4100 device becomes unresponsive or crashes, leading to a denial-of-service condition.
8. Industrial processes relying on the SIMATIC CN 4100 device are disrupted or halted.

Impact

Successful exploitation of CVE-2026-22924 can result in a denial-of-service condition on the SIMATIC CN 4100 device, disrupting critical industrial processes. This may lead to operational downtime, financial losses, and potential safety hazards. The vulnerability affects all versions of SIMATIC CN 4100 prior to V5.0, potentially impacting a wide range of industrial sectors that rely on these devices for network communication.

Recommendation

• Upgrade SIMATIC CN 4100 devices to version V5.0 or later to remediate CVE-2026-22924.
• Implement network segmentation and access control measures to limit exposure of SIMATIC CN 4100 devices to untrusted networks.
• Deploy the Sigma rule “Detect SIMATIC CN 4100 Unauthenticated Connection Attempts” to identify suspicious unauthenticated connection patterns to the device.
• Monitor network traffic to SIMATIC CN 4100 devices for unusually high connection rates and resource consumption.
• Apply the mitigations recommended by Siemens in their security advisory SSA-032379.