Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP

Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version V3.1.7 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). Siemens is preparing fixes and recommends specific mitigations for products where fixes are not or not yet available.

The following versions of Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP are affected:

SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) vers:intdot/>=3.1.7

SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) vers:intdot/>=3.1.7

SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) vers:intdot/>=3.1.7

SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) vers:intdot/>=3.1.7

SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) vers:intdot/>=3.1.7

Critical Infrastructure Sectors: Critical Manufacturing, Transportation Systems, Energy, Healthcare and Public Health, Financial Services, Government Services and Facilities

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Germany

Product Status: known_affected

Mitigation Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.

Mitigation Only build and run applications from trusted sources.

None available Currently no fix is available

Product Status: known_affected

Mitigation Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.

Mitigation Only build and run applications from trusted sources.

None available Currently no fix is available

Product Status: known_affected

Mitigation Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.

Mitigation Only build and run applications from trusted sources.

None available Currently no fix is available

Product Status: known_affected

Mitigation Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.

Mitigation Only build and run applications from trusted sources.

None available Currently no fix is available

Product Status: known_affected

Mitigation Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.

Mitigation Only build and run applications from trusted sources.

None available Currently no fix is available

Relevant CWE: CWE-311 Missing Encryption of Sensitive Data

Siemens ProductCERT reported these vulnerabilities to CISA.

General Recommendations

As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for Industrial Security ( y), and to follow the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at:

For further inquiries on security vulnerabilities in Siemens products and solutions, please the Siemens ProductCERT:

The use of Siemens Security Advisories is subject to the terms and conditions listed on: .

Recommended Practices

CISA recommends users take defensive measures to minimize the exploitation risk of this vulnerability.

Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet.

Locate control system networks and remote devices behind firewalls and isolate them from business networks.

When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most recent version available. Also recognize VPN is only as secure as its connected devices.

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.

Advisory Conversion Disclaimer

This ICSA is a verbatim republication of Siemens ProductCERT SSA-457936 from a direct conversion of the vendor's Common Security Advisory Framework (CSAF) advisory. This is republished to CISA's website as a means of increasing visibility and is provided "as-is" for informational purposes only. CISA is not responsible for the editorial or technical accuracy of republished advisories and provides no warranties of any kind regarding any information contained within this advisory. Further, CISA does not endorse any commercial product or service. Please Siemens ProductCERT directly for any questions regarding this advisory.

Initial Release Date: 2026-10-13

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