1. EXECUTIVE SUMMARY
- CVSS v3 9.8
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Schneider Electric
- Equipment: Communication modules for Modicon M580 and Quantum controllers
- Vulnerability: Out-of-bounds Write
2. RISK EVALUATION
Successful exploitation of this vulnerability could allow a stack overflow attack, which could result in loss of confidentiality, integrity, and denial of service of the device.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
Schneider Electric reports that the following communication modules for Modicon M580 and Quantum controllers are affected by a vulnerability in 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 possible stack overflow in dhcp server was discovered in Wind River VxWorks through 6.8.
CVE-2021-29999 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
3.3 BACKGROUND
- CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities, Critical Manufacturing, Energy
- COUNTRIES/AREAS DEPLOYED: Worldwide
- COMPANY HEADQUARTERS LOCATION: France
3.4 RESEARCHER
Schneider Electric reported this vulnerability to CISA.
4. MITIGATIONS
Schneider Electric has identified the following specific remediations and mitigations users can apply to reduce risk:
- Modicon M580 communication modules BMENOC BMENOC0321: Version SV1.10 of BMENOC0321 includes a fix for this vulnerability and is available for download here: https://www.se.com/ww/en/product/BMENOC0321/m580- noc-control/
- Schneider Electric is establishing a remediation plan for all future versions of BMECRA, BMXCRA and 140CRA that will include a fix for this vulnerability. They will update SEVD-2025-014-03 when the remediation is available. Until then, users should immediately implement a firewall to allow only authorized traffic on 67/UDP and 68/UDP ports to reduce the risk of exploit.
Schneider Electric strongly recommends the following industry cybersecurity best practices.
- Locate control and safety system networks and remote devices behind firewalls and isolate them from the business network.
- Install physical controls so no unauthorized personnel can access your industrial control and safety systems, components, peripheral equipment, and networks.
- Place all controllers in locked cabinets and never leave them in the “Program” mode.
- Never connect programming software to any network other than the network intended for that device.
- Scan all methods of mobile data exchange with the isolated network such as CDs, USB drives, etc. before use in the terminals or any node connected to these networks.
- Never allow mobile devices that have connected to any other network besides the intended network to connect to the safety or control networks without proper sanitation.
- Minimize network exposure for all control system devices and systems and ensure that they are not accessible from the Internet.
- When remote access is required, use secure methods, such as virtual private networks (VPNs). Recognize that VPNs may have vulnerabilities and should be updated to the most current version available. Also, understand that VPNs are only as secure as the connected devices.
For more information refer to the Schneider Electric Recommended Cybersecurity Best
Practices document.
For more information, see Schneider Electric security notification “SEVD-2025-014-03 Wind River VxWorks DHCP server vulnerability”
Additional information about the vulnerability can be found on the Wind River site.
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.
No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.
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