Critical Siemens UMC Flaw Enables Remote Code Execution by Attackers
A critical vulnerability (CVE-2024-49775) has been discovered in Siemens’ User Management Component (UMC), which could allow unauthenticated remote attackers to execute arbitrary code on affected systems. This flaw, classified as a heap-based buffer overflow, impacts various Siemens products including Opcenter, SIMATIC PCS neo, SINEC NMS, and TIA Portal. The vulnerability is rated with a high CVSS score of 9.8, making it a severe risk to industrial environments. Siemens is actively working on updates, but until patches are released, customers are advised to follow the recommended mitigations, such as port restrictions and system updates. Immediate action is recommended to protect against potential attacks.
Critical Vulnerability Found in Siemens UMC: Immediate Action Required
Siemens has alerted the cybersecurity community to a critical vulnerability within its User Management Component (UMC) that could allow remote attackers to execute arbitrary code on affected systems. The flaw, identified as CVE-2024-49775, stems from a heap-based buffer overflow in the UMC component, and it poses a significant risk to industrial control systems.
Vulnerability Overview
The vulnerability allows unauthenticated remote attackers to exploit the issue without requiring user interaction, making it especially dangerous. Once exploited, the attacker could execute arbitrary code on the affected system, potentially leading to data breaches, operational disruptions, or manipulation of industrial control systems.
Siemens has issued a Security Advisory (SSA-928984) in response to the vulnerability, urging customers to take immediate action and apply mitigations or patches to secure their systems.
The vulnerability has been classified as critical, with a CVSS v3.1 base score of 9.8 and a CVSS v4.0 base score of 9.3. The flaw is classified under CWE-122: Heap-Based Buffer Overflow, indicating an issue with improper memory handling that leaves systems vulnerable to exploitation.
Impacted Products and Solutions
The following Siemens products have been identified as vulnerable due to the UMC component integration:
| Product | Version | CVE ID | Remediation |
| Opcenter Execution Foundation | All versions | CVE-2024-49775 | No fix available. Follow recommendations in Workarounds and Mitigations. |
| Opcenter Intelligence | All versions | CVE-2024-49775 | No fix available. Follow recommendations in Workarounds and Mitigations. |
| Opcenter Quality | All versions | CVE-2024-49775 | No fix available. Follow recommendations in Workarounds and Mitigations. |
| Opcenter RDL | All versions | CVE-2024-49775 | No fix available. Follow recommendations in Workarounds and Mitigations. |
| SINEC NMS | UMC < V2.15 | CVE-2024-49775 | Update to V3.0 SP2 or later and UMC to V2.15 or later. Contact Siemens support. |
| Totally Integrated Automation Portal | Open for details | CVE-2024-49775 | Fixed versions available; see Siemens support documentation for details. |
Mitigation Strategies and Recommendations
Siemens has issued several workarounds and mitigation measures to help reduce the risk posed by this vulnerability:
-
Port Restrictions: Filter ports 4002 and 4004 to allow connections only from trusted IP addresses within the UMC network. If no real-time server machines (RT servers) are in use, Siemens recommends blocking port 4004 entirely.
-
System Updates: Siemens has released updated versions for some affected products, including SIMATIC PCS neo and SINEC NMS. For SINEC NMS, upgrading to V3.0 SP2 or later and UMC to V2.15 or later is recommended. Users of SIMATIC PCS neo-V5.0 should upgrade to Version V5.0 Update 1 or newer.
-
Network Segmentation: To isolate vulnerable systems, Siemens recommends segmenting the network and restricting access to only trusted devices.
Security Best Practices
Siemens emphasizes the importance of adhering to best practices for industrial security, including the following:
- Follow Siemens' Operational Guidelines for Industrial Security to configure a protected IT environment and ensure secure network access.
- Apply Patches Promptly: While some patches are available, others are still under development. Customers are urged to stay informed about new fixes and apply them as soon as they are released.
- Defense-in-Depth Strategies: Siemens and CISA (Cybersecurity and Infrastructure Security Agency) both recommend adopting a multi-layered security approach to safeguard industrial control systems from exploitation.
Impact on Industrial Control Systems
This vulnerability has the potential for widespread impact, particularly in critical infrastructure sectors such as energy, manufacturing, and industrial automation. If exploited, the vulnerability could result in unauthorized control of industrial processes, operational disruptions, data exfiltration, or the manipulation of control systems.
While there have been no reports of active exploitation, cybersecurity experts advise organizations to apply mitigations immediately, as the risk of exploitation remains high.
Conclusion
The CVE-2024-49775 vulnerability in Siemens’ UMC component underscores the critical need for robust cybersecurity practices in industrial environments. Siemens continues to develop and release patches for the affected products, and the company strongly advises customers to implement the recommended mitigations and stay up-to-date with security advisories.
As industrial control systems are integral to global infrastructure, prompt action is crucial to mitigate the risks associated with this critical vulnerability.
