Technical Report: Vulnerability Analysis of Schneider Electric Communication Modules for Modicon M580 & Quantum Controllers
1. EXECUTIVE SUMMARY
- CVSS v3 Score: 9.8
- Exploitation: Remotely exploitable with low attack complexity
- Vendor: Schneider Electric
- Affected Equipment: Communication modules for Modicon M580 and Quantum controllers
- Vulnerability Type: Out-of-bounds Write
2. RISK EVALUATION
The successful exploitation of this vulnerability could lead to a stack overflow attack, potentially resulting in loss of confidentiality, integrity, and denial of service for the affected devices. This poses significant risks to operational continuity and data security within critical infrastructure sectors.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
Schneider Electric has identified the following communication modules as vulnerable due to an issue in the VxWorks operating system:
- Modicon M580 communication modules BMENOC BMENOC0321: Versions prior to SV1.10
- Modicon M580 communication modules BMECRA BMECRA31210: All versions
- Modicon M580/Quantum communication modules BMXCRA BMXCRA31200: All versions
- Modicon M580/Quantum communication modules BMXCRA BMXCRA31210: All versions
- Modicon Quantum communication modules 140CRA 140CRA31908: All versions
- Modicon Quantum communication modules 140CRA 140CRA31200: All versions
3.2 VULNERABILITY OVERVIEW
3.2.1 OUT-OF-BOUNDS WRITE CWE-787
A potential stack overflow vulnerability was discovered in the DHCP server of Wind River VxWorks, affecting versions up to 6.8. This vulnerability has been cataloged as CVE-2021-29999, with a CVSS v3 base score of 9.8, indicating a critical level of risk.
3.3 BACKGROUND
- Critical Infrastructure Sectors: Commercial Facilities, Critical Manufacturing, Energy
- Deployment Areas: Worldwide
- Company Headquarters: France
3.4 RESEARCHER
Schneider Electric has reported this vulnerability to the Cybersecurity and Infrastructure Security Agency (CISA).
4. MITIGATIONS
To mitigate the risks associated with this vulnerability, Schneider Electric recommends the following actions:
- Update Affected Modules: Users of Modicon M580 communication modules BMENOC BMENOC0321 should upgrade to Version SV1.10, which includes a fix for this vulnerability. The update is available for download here.
- Future Remediation Plans: Schneider Electric is developing a remediation plan for all future versions of BMECRA, BMXCRA, and 140CRA modules. Users should monitor SEVD-2025-014-03 for updates. In the interim, it is advised to implement a firewall to restrict traffic on UDP ports 67 and 68.
Additionally, Schneider Electric emphasizes the importance of adhering to industry cybersecurity best practices:
- Network Isolation: Place control and safety system networks behind firewalls and isolate them from business networks.
- Physical Security: Implement physical controls to prevent unauthorized access to industrial control systems.
- Secure Configuration: Store all controllers in locked cabinets and avoid leaving them in “Program” mode.
- Controlled Software Access: Ensure programming software is only connected to the intended network.
- Data Exchange Security: Scan all mobile data exchange methods before use in connected terminals.
- Device Sanitation: Prevent mobile devices from connecting to safety or control networks without proper sanitation.
- Minimize Exposure: Limit network exposure for control system devices and ensure they are not accessible from the Internet.
- Secure Remote Access: Use secure methods like VPNs for remote access, while keeping in mind that VPNs may have vulnerabilities.
For further information, refer to Schneider Electric’s Recommended Cybersecurity Best Practices document.
Organizations are encouraged to implement recommended cybersecurity strategies for proactive defense of ICS assets, as detailed on the CISA website.
No known public exploitation of this vulnerability has been reported to CISA at this time.
5. UPDATE HISTORY
- February 27, 2025: Initial Publication
