---
title: "Critical Siemens Industrial Device Flaw Enables Denial-of-Service Attacks"
short_title: "Siemens devices vulnerable to DoS attacks"
description: "Siemens discloses a high-severity null pointer dereference vulnerability (CVE-2025-40833) in multiple industrial devices, enabling attackers to cause denial-of-service conditions."
author: "Vitus"
date: 2024-10-02
categories: [Cybersecurity, Vulnerabilities]
tags: [siemens, cve-2025-40833, dos, industrial-security, ot-security]
score: 0.85
cve_ids: [CVE-2025-40833]
---
## TL;DR
Siemens has identified a critical null pointer dereference vulnerability (CVE-2025-40833) affecting over 150 industrial devices, including SCALANCE, RUGGEDCOM, and SIMATIC products. Exploitation could lead to denial-of-service (DoS) conditions, requiring manual restarts. Siemens has released patches for some devices and recommends mitigation measures for others.
Main Content
Critical Vulnerability in Siemens Industrial Devices Exposes OT Networks to DoS Attacks
Siemens has issued a security advisory addressing a high-severity vulnerability (CVE-2025-40833) in its industrial devices, which could allow attackers to trigger denial-of-service (DoS) conditions. The flaw, rated 7.5 (CVSS v3.1), stems from a null pointer dereference issue when processing specially crafted IPv4 requests. Affected devices span multiple product lines, including SCALANCE, RUGGEDCOM, SIMATIC, and SINAMICS, widely used in critical manufacturing and operational technology (OT) environments.
### Key Points
- Vulnerability: Null pointer dereference (CVE-2025-40833) in Siemens industrial devices.
- Impact: Attackers can cause DoS conditions, requiring manual system restarts.
- Affected Products: Over 150 devices, including SCALANCE routers, RUGGEDCOM switches, SIMATIC PLCs, and SINAMICS drives.
- Severity: High (CVSS 7.5), with potential for widespread disruption in OT networks.
- Mitigation: Siemens has released patches for some devices and recommends network segmentation, access restrictions, and disabling vulnerable Ethernet ports where fixes are unavailable.
Technical Details
#### Vulnerability Overview
The vulnerability (CVE-2025-40833) occurs due to a null pointer dereference in the IPv4 request processing mechanism of affected Siemens devices. When exploited, this flaw causes the device to crash, leading to a DoS condition. Recovery requires a manual restart, making it particularly disruptive for industrial environments where uptime is critical.
#### Affected Systems
The flaw impacts a broad range of Siemens industrial products, including:
- SCALANCE routers and switches (e.g., SCALANCE X, M, and W series).
- RUGGEDCOM industrial communication devices (e.g., RM1224 LTE).
- SIMATIC PLCs and distributed I/O systems (e.g., S7-1500, ET 200SP).
- SINAMICS drives and SITOP power supplies.
- SIPLUS variants of affected products.
A full list of vulnerable devices is available in the Siemens advisory.
#### Attack Vector
Exploitation requires network access to the targeted device. Attackers can send maliciously crafted IPv4 packets to trigger the vulnerability, causing the device to crash. No authentication is required, increasing the risk of remote exploitation in exposed OT networks.
Impact Assessment
#### Operational Disruption
The vulnerability poses a significant risk to industrial operations, particularly in sectors like manufacturing, energy, and critical infrastructure. A successful DoS attack could halt production lines, disrupt communication between OT devices, and lead to costly downtime.
#### Exploitation Risk
While there are no reports of active exploitation as of this publication, the low complexity of the attack and the high availability of vulnerable devices make this a prime target for threat actors. Organizations with exposed industrial networks are at heightened risk.
#### Compliance and Regulatory Concerns
Industries relying on Siemens devices may face compliance challenges, particularly under frameworks like NIST SP 800-82, IEC 62443, and NERC CIP. Failure to patch or mitigate the vulnerability could result in non-compliance with cybersecurity standards for critical infrastructure.
Mitigation Steps
Siemens has provided patches and mitigation strategies to address the vulnerability:
#### Patches and Updates
- SCALANCE, RUGGEDCOM, and SIMATIC devices: Update to the latest firmware versions (e.g., V8.3, V6.6.0, or V3.2.0) as specified in the Siemens advisory.
- SIMATIC CFU and S7-410 CPUs: Apply updates to V2.0.0 or V10.2 where available.
#### Workarounds and Mitigations
For devices where patches are not yet available, Siemens recommends:
1. Disable Ethernet ports on vulnerable CPUs and use communication modules (e.g., CP) for network traffic.
2. Restrict network access to trusted IP addresses only.
3. Isolate OT networks from business networks using firewalls and segmentation.
4. Monitor network traffic for suspicious IPv4 requests targeting affected devices.
#### General Security Best Practices
- Follow Siemens’ operational guidelines for industrial security (Download here).
- Implement defense-in-depth strategies, including intrusion detection systems (IDS) and regular vulnerability assessments.
- Audit and inventory all Siemens devices in your network to identify vulnerable systems.
### Affected Systems
The following Siemens product families are affected by CVE-2025-40833. Refer to the official advisory for a complete list of vulnerable device models and versions.
| Product Family | Examples of Affected Devices | Vulnerable Versions |
|--------------------------|------------------------------------------------------|----------------------------------|
| SCALANCE | SCALANCE X, M, W, and S series routers/switches | All versions < V8.3 |
| RUGGEDCOM | RM1224 LTE(4G) EU/NAM | All versions < V8.3 |
| SIMATIC | S7-1500, S7-300, ET 200SP CPUs | All versions |
| SINAMICS | G120, G150, S120 drives | All versions |
| SITOP | PSU8600 power supplies | All versions |
| SIPLUS | SIPLUS variants of SCALANCE and SIMATIC devices | All versions |
Conclusion
The discovery of CVE-2025-40833 underscores the growing cybersecurity risks facing industrial environments. With over 150 Siemens devices affected, organizations must act swiftly to patch vulnerable systems or implement mitigation measures to prevent potential DoS attacks. Given the critical role of these devices in OT networks, failure to address this vulnerability could lead to severe operational disruptions and financial losses.
Siemens’ proactive release of patches and mitigation guidance is commendable, but the onus is on asset owners to prioritize updates and secure their networks. As OT cyber threats evolve, collaboration between vendors, security researchers, and end-users remains essential to safeguarding critical infrastructure.
## References
[^1]: Siemens ProductCERT. "SSA-392349: Denial of Service Vulnerability in Siemens Industrial Devices". Retrieved 2024-10-02.
[^2]: CISA. "ICSA-26-134-06: Siemens Industrial Devices". Retrieved 2024-10-02.
[^3]: MITRE. "CWE-476: NULL Pointer Dereference". Retrieved 2024-10-02.