ICS Alert (ICS-ALERT-11-332-01A)

Siemens Automation License Manager Vulnerabilities (Update A)

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This Alert Update is a follow-up to the original ICS-CERT Alert titled “ICS-ALERT-11-332-01—Siemens Automatic License Manager” that was published November 28, 2011 on the ICS-CERT web page.

ICS-CERT is aware of a public report of four vulnerabilities with proof-of-concept (PoC) exploit code affecting the Siemens Automation License Manager (ALM). According to this report, the vulnerabilities are remotely exploitable. This report was released by Luigi Auriemma without coordination with Siemens, ICS-CERT, or any other coordinating entity known to ICS-CERT.

ICS-CERT has coordinated the report with Siemens, who is working to confirm the report and identify mitigations. ICS-CERT is issuing this alert to provide early notice of the report and identify baseline mitigations for reducing risks to these and other cybersecurity attacks.

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The ALM is a component of Siemens industrial software and is necessary for licensing Siemens supervisory control and data acquisition (SCADA), human-machine interface (HMI), and engineering software.

The report includes vulnerability details and PoC exploit code for four vulnerabilities. Siemens has analyzed the vulnerability report and offered the following vulnerability characterization information.

Vulnerability TypeExploitabilityImpact
Buffer OverflowRemoteDenial of Service (DoS) / Possible Remote Code Execution
Improper Input ValidationRemoteWrite access to file system allowing arbitrary file deletion

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Please report any issues affecting control systems in critical infrastructure environments to ICS-CERT.


ICS-CERT released a follow-up advisory, ICSA-11-361-01—Siemens Automatic License Manager, to the ICS-CERT Web site on December 27, 2011.


ICS-CERT is currently coordinating with Siemens to identify mitigations.

ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these
vulnerabilities. Specifically, users should:

  • Minimize network exposure for all control system devices. Control system devices should not directly face the Internet.a
  • Locate control system networks and devices behind firewalls, and isolate them from the business network.
  • If remote access is required, employ secure methods, such as Virtual Private Networks (VPNs), recognizing that VPN is only as secure as the connected devices.

ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to taking defensive measures.

The Control Systems Security Program (CSSP) also provides a recommended practices section for control systems on the US-CERT website. Several recommended practices are available for reading or download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

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

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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