Siemens User Management Component (UMC)

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 8.7
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Siemens
• Equipment: User Management Component (UMC)
• Vulnerabilities: Out-of-bounds Read, Out-of-bounds Write

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow an unauthenticated remote attacker to cause a denial-of-service condition.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Siemens reports that the following products are affected:

• Siemens SIMATIC PCS neo V4.1: All versions
• Siemens SIMATIC PCS neo V5.0: All versions
• Siemens SINEC NMS: All versions
• Siemens SINEMA Remote Connect: All versions
• Siemens Totally Integrated Automation Portal (TIA Portal) V17: All versions
• Siemens Totally Integrated Automation Portal (TIA Portal) V18: All versions
• Siemens Totally Integrated Automation Portal (TIA Portal) V19: All versions
• Siemens Totally Integrated Automation Portal (TIA Portal) V20: All versions
• Siemens User Management Component (UMC): All versions prior to V2.15.1.1

3.2 VULNERABILITY OVERVIEW

3.2.1 OUT-OF-BOUNDS READ CWE-125

The affected products contain a out-of-bound read buffer overflow vulnerability in the integrated UMC component. This could allow an unauthenticated remote attacker to cause a denial-of-service condition.

CVE-2025-30174 has been assigned to this vulnerability. A CVSS v3.1 base score of 7.5 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

A CVSS v4 score has also been calculated for CVE-2025-30174. A base score of 8.7 has been calculated; the CVSS vector string is (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N).

3.2.2 OUT-OF-BOUNDS WRITE CWE-787

The affected products contain a out-of-bound write buffer overflow vulnerability in the integrated UMC component. This could allow an unauthenticated remote attacker to cause a denial-of-service condition.

CVE-2025-30175 has been assigned to this vulnerability. A CVSS v3.1 base score of 7.5 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

A CVSS v4 score has also been calculated for CVE-2025-30175. A base score of 8.7 has been calculated; the CVSS vector string is (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N).

3.2.3 OUT-OF-BOUNDS READ CWE-125

The affected products contain a out-of-bound read buffer overflow vulnerability in the integrated UMC component. This could allow an unauthenticated remote attacker to cause a denial-of-service condition.

CVE-2025-30176 has been assigned to this vulnerability. A CVSS v3.1 base score of 7.5 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

A CVSS v4 score has also been calculated for CVE-2025-30176. A base score of 8.2 has been calculated; the CVSS vector string is (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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 reported these vulnerabilities to CISA.

4. MITIGATIONS

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

• All affected products: In non-networked scenarios/deployments block TCP ports 4002 and 4004 on machines with UMC installed. In addition if no RT server machines are used, port 4004 can be blocked completely
• SIMATIC PCS neo V4.1: Currently no fix is planned
• SIMATIC PCS neo V5.0, SINEMA Remote Connect: Currently no fix is available
• User Management Component (UMC): Update to V2.15.1.1 or later version
• SINEC NMS, Totally Integrated Automation Portal (TIA Portal) V17, Totally Integrated Automation Portal (TIA Portal) V18, Totally Integrated Automation Portal (TIA Portal) V19, Totally Integrated Automation Portal (TIA Portal) V20: Update UMC to V2.15.1.1 or later

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-614723 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.

CISA also recommends users take the following measures to protect themselves from social engineering attacks:

• Do not click web links or open attachments in unsolicited email messages.
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time.

5. UPDATE HISTORY

May 15, 2025: Initial Republication of Siemens Advisory SSA-614723

• Siemens