ICS Advisory (ICSA-13-233-01)

Siemens COMOS Privilege Escalation Vulnerability

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Siemens has notified ICS-CERT of a privilege escalation vulnerability in the Siemens COMOS database application. Siemens has produced a patch that mitigates this vulnerability.


The following Siemens COMOS versions are affected:

  • All COMOS versions prior to 9.1
  • COMOS 9.1: all versions prior to LyraUpdate458 (Update 458)
  • COMOS 9.2: all versions prior to V092_Upd06_Patch037 (
  • COMOS 10.0: all versions prior to V100_SP03_Patch019 (


This vulnerability may allow attackers to escalate their privileges for database access. This could allow compromise of the integrity of the database. The attacker would need local access as an authenticated user to exploit the vulnerability.

Impact to individual organizations depends on many factors that are unique to each organization. ICS‑CERT recommends that organizations evaluate the impact of this vulnerability based on their operational environment, architecture, and product implementation.


Siemens is a multinational company headquartered in Munich, Germany.

COMOS is an object-oriented database system that supports collecting, processing, saving, and distributing information. COMOS is used across many engineering domains, including functional engineering of plans and machines, engineering and design, automation and process control planning, and asset and plant management. COMOS offices are located world-wide in Europe, the Americas, and Asia.




A vulnerability in the client application of COMOS might allow an attacker privilege escalation to the database using the COMOS graphical user interface. This interface is intended for local authenticated users to access the database through the client application.

CVE-2013-4943b has been assigned to this vulnerability. A CVSS v2 base score of 7.2 has been assigned by the vendor; the CVSS vector string is (AV:L/AC:L/Au:N/C:C/I:C/A:C).c



The attacker would need local access as an authenticated user to exploit the vulnerability.


No known public exploits specifically target this vulnerability.


An attacker with a low skill would be able to exploit this vulnerability.


Siemens provides the following updates for COMOS Versions 9.1, 9.2, and 10.0 that resolves this vulnerability:

  • COMOS v9.1 use patch LyraUpdate458 (Update 458)
  • COMOS v9.2 use patch V092_Upd06_Patch037 (
  • COMOS v10.0 use patch V100_SP03_Patch019 (

The updates are available at the Siemens customer support site here:


For further information, please find a description and release notes in the Siemens Security Advisory here:


ICS‑CERT encourages asset owners to take additional defensive measures to protect against this and other cybersecurity risks.

  • Minimize network exposure for all control system devices. Critical devices should not directly face 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 VPN is only as secure as the connected devices.

ICS-CERT also provides a section for control systems security recommended practices on the ICS-CERT Web page. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.d ICS‑CERT reminds organizations to perform proper impact analysis and risk assessment prior to taking defensive measures.

Additional mitigation guidance and recommended practices are publicly available in the ICS‑CERT Technical Information Paper, ICS-TIP-12-146-01B—Targeted Cyber Intrusion Mitigation Strategies,e that is available for download from the ICS-CERT Web page (http://ics-cert.us-cert.gov/).

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

  • aCWE-269: Improper Privilege Management, http://cwe.mitre.org/data/definitions/269.html, Web site last accessed August 21, 2013.
  • bNVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-4943, Web site last accessed August 21, 2013.
  • cCVSS Calculator, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:L/AC:L/Au:N/C:C/I:C/A:C, Web site last visited August 21, 2013.
  • dCSSP Recommended Practices, http://ics-cert.us-cert.gov/content/recommended-practices, Web site last accessed August 21, 2013.
  • eTargeted Cyber Intrusion Detection and Mitigation Strategies, http://ics-cert.us-cert.gov/tips/ICS-TIP-12-146-01B, Web site last accessed August 21, 2013.

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://us-cert.cisa.gov/ics 
or incident reporting:  https://us-cert.cisa.gov/report

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