ICS Advisory (ICSA-20-252-03)

Siemens License Management Utility

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1. EXECUTIVE SUMMARY

  • CVSS v3 7.8
  • ATTENTION: Low skill level to exploit
  • Vendor: Siemens
  • Equipment: License Management Utility
  • Vulnerability: Execution with Unnecessary Privileges

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow local users to escalate privileges.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of License Management Utility (LMU), a license management system, are affected:

  • LMU: All versions prior to v2.4

3.2 VULNERABILITY OVERVIEW

3.2.1    EXECUTION WITH UNNECESSARY PRIVILEGES CWE-250

A specific service of the affected application is executed with local SYSTEM privileges on the server while its configuration can be modified by local users. 

CVE-2020-10056 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

  • CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities Sector, Government Facilities Sector
  • COUNTRIES/AREAS DEPLOYED: Worldwide
  • COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Bundesamt für Sicherheit in der Informationstechnik (BSI) reported this vulnerability to Siemens.

4. MITIGATIONS

Siemens has released an updated version (v2.4) of LMU, and recommends users install this update on all affected systems.
Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:

  • Apply security hardening of the Windows Server, where LMU is installed on, in accordance with corporate security policies or up-to-date hardening guidelines.
  • Ensure only trusted persons have access to the system and avoid the configuration of additional local accounts on the server.

As a general security measure, Siemens strongly recommends protecting network access to affected products with appropriate mechanisms. It is advised to follow recommended security practices in order to run the devices in a protected IT environment.
For more information please see Siemens Advisory: SSA-709003

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

  • Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
  • Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
  • When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that 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 us-cert.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on us-cert.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.

No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely.


Contact Information

For any questions related to this report, please contact the CISA at:

Email: CISAservicedesk@cisa.dhs.gov
Toll Free: 1-888-282-0870

For industrial control systems cybersecurity information:  https://www.us-cert.gov/ics 
or incident reporting:  https://www.us-cert.gov/report

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