Siemens SINUMERIK Systems

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 6.8
• ATTENTION: Low attack complexity
• Vendor: Siemens
• Equipment: SINUMERIK systems
• Vulnerability: Insertion of Sensitive Information into Log File

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow a local authenticated user with low privileges to read passwords and use it to impersonate a user with higher privileges.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of Siemens SINUMERIK systems are affected:

• SINUMERIK 828D V4: All versions prior to V4.95 SP3
• SINUMERIK 840D sl V4: All versions prior to V4.95 SP3 in connection with using Create MyConfig (CMC) V4.8 SP1 HF6 and prior
• SINUMERIK ONE prior to V6.23: All versions prior to V6.23 in connection with using Create MyConfig (CMC) V6.6 and prior
• SINUMERIK ONE prior to V6.15 SP4: All versions prior to V6.15 SP4 in connection with using Create MyConfig (CMC) V6.6 and prior

3.2 Vulnerability Overview

3.2.1 INSERTION OF SENSITIVE INFORMATION INTO LOG FILE CWE-532

Affected systems, that have been provisioned with Create MyConfig (CMC), contain a Insertion of Sensitive Information into Log File vulnerability. This could allow a local authenticated user with low privileges to read sensitive information and thus circumvent access restrictions.

CVE-2024-43781 has been assigned to this vulnerability. A CVSS v3.1 base score of 5.5 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

A CVSS v4 score has also been calculated for CVE-2024-43781. A base score of 6.8 has been calculated; the CVSS vector string is (CVSS4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/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 reported this vulnerability to CISA.

4. MITIGATIONS

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

• SINUMERIK 828D V4: Update to V4.95 SP3 or later version
• SINUMERIK 840D sl V4: Update to V4.95 SP3 or later version
• SINUMERIK ONE prior to V6.23: Update to V6.23 or later version
• SINUMERIK ONE prior to V6.15 SP4: Update to V6.15 SP4 or later version

Delete the file(s) manually (after using CMC):

• on an NCU: /card/user/sinumerik/hmi/log/sltrc/uptrace.out
• on an IPC: C:\ProgramData\Siemens\MotionControl\user\sinumerik\hmi\log\sltrc\uptrace.out

and the corresponding backup of the tracefile, uptrace.out.bak. Replace trace configuration to switch off trace for the future.

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-097786 in HTML and CSAF.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability, 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), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is 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/ics. 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/ics 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. This vulnerability is not exploitable remotely.

5. UPDATE HISTORY

• September 12, 2024: Initial Publication

• Siemens