Siemens SINEC OS

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).

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1. EXECUTIVE SUMMARY

• CVSS v4 2.3
• ATTENTION: Exploitable from adjacent network
• Vendor: Siemens
• Equipment: SINEC OS
• Vulnerabilities: Uncontrolled Resource Consumption, Exposure of Sensitive Information to an Unauthorized Actor

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow an attacker to access non-sensitive information without authentication or potentially cause a temporary denial of service.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Siemens reports that the following products are affected:

• Siemens RUGGEDCOM RST2428P (6GK6242-6PA00): All versions

3.2 VULNERABILITY OVERVIEW

3.2.1 UNCONTROLLED RESOURCE CONSUMPTION CWE-400

The affected device may be susceptible to resource exhaustion when subjected to high volumes of query requests. This could allow an attacker to cause a temporary denial of service, with the system recovering once the activity stops.

CVE-2025-40802 has been assigned to this vulnerability. A CVSS v3.1 base score of 3.1 has been calculated; the CVSS vector string is (CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L).

A CVSS v4 score has also been calculated for CVE-2025-40802. A base score of 2.3 has been calculated; the CVSS vector string is (CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N).

3.2.2 EXPOSURE OF SENSITIVE INFORMATION TO AN UNAUTHORIZED ACTOR CWE-200

The affected device exposes certain non-critical information from the device. This could allow an unauthenticated attacker to access sensitive data, potentially leading to a breach of confidentiality.

CVE-2025-40803 has been assigned to this vulnerability. A CVSS v3.1 base score of 3.1 has been calculated; the CVSS vector string is (CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N).

A CVSS v4 score has also been calculated for CVE-2025-40803. A base score of 2.3 has been calculated; the CVSS vector string is (CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Siemens ProductCERT reported these vulnerabilities to CISA.

4. MITIGATIONS

Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:

• RUGGEDCOM RST2428P (6GK6242-6PA00): Create a firewall rule that blocks the UDP ports if not required. The device uses UDP 34964 and one port in range 49152-65535 for discovery protocols like LLDP, DCP, MRP etc.

As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following recommendations in the product manuals.

Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage

For more information see the associated Siemens security advisory SSA-494539 in HTML and CSAF.

CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities, such as:

• Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.
• Locate control system networks and remote devices behind firewalls and isolating them from business networks.
• When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs). Recognize VPNs may have vulnerabilities, should be updated to the most recent version available, and are only as secure as the 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.

No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time. These vulnerabilities are not exploitable remotely. These vulnerabilities have a high attack complexity.

5. UPDATE HISTORY

• September 11, 2025: Initial Republication of Siemens ProductCERT SSA-494539

• Siemens