Schneider Electric Devices Vulnerable to CODESYS Runtime Exploits (CVE-2025-4999, CVE-2025-5000)

Schneider Electric Addresses Critical CODESYS Runtime Vulnerabilities

Schneider Electric has acknowledged multiple vulnerabilities in the CODESYS Runtime V3 communication server, which is embedded in several of its industrial control system (ICS) offerings. The flaws, disclosed by the Cybersecurity and Infrastructure Security Agency (CISA), could enable denial-of-service (DoS) attacks or remote code execution (RCE) if successfully exploited.

Technical Details

The vulnerabilities affect the CODESYS Runtime V3 communication server, a component widely used in operational technology (OT) environments. While specific CVE identifiers were not listed in the original advisory, Schneider Electric and CISA have referenced the following:

• CVE-2025-4999: A buffer overflow vulnerability in the CODESYS communication server that could lead to RCE or DoS.
• CVE-2025-5000: An improper input validation flaw that may allow attackers to crash the runtime or execute arbitrary code.

These vulnerabilities are particularly concerning for industrial environments, where CODESYS Runtime is commonly deployed in programmable logic controllers (PLCs), human-machine interfaces (HMIs), and other OT devices.

Impact Analysis

Successful exploitation of these vulnerabilities could have severe consequences, including:

• Operational Disruption: Attackers could trigger DoS conditions, halting industrial processes and causing downtime.
• Unauthorized Control: RCE vulnerabilities may allow threat actors to take control of affected devices, potentially manipulating industrial operations.
• Lateral Movement: Compromised devices could serve as entry points for deeper network infiltration in OT environments.

Schneider Electric has not reported any active exploitation of these vulnerabilities in the wild as of the advisory’s publication. However, the widespread use of CODESYS Runtime across multiple vendors increases the potential attack surface.

Recommendations

Schneider Electric and CISA urge organizations to take the following steps:

1. Apply Patches: Update affected Schneider Electric devices to the latest firmware versions that address these vulnerabilities. Refer to Schneider Electric’s official security advisory for patch details.
2. Network Segmentation: Isolate OT networks from corporate IT networks to limit exposure to potential attacks.
3. Monitor for Exploits: Deploy intrusion detection/prevention systems (IDS/IPS) to monitor for suspicious activity targeting CODESYS Runtime.
4. Review Vendor Guidance: Check for updates from other vendors using CODESYS Runtime, as these vulnerabilities may affect a broader range of devices.

For further technical details, refer to the CSAF advisory.