U.S. Flag Official website of the Department of Homeland Security
U.S. Department of Homeland Security Seal. ICS-CERT. Industrial Control Systems Cyber Emergency Response Team.
TLP:WHITE

Alert (ICS-ALERT-11-161-01)

Siemens S7-1200 PLC Vulnerabilities

Original release date: June 10, 2011 | Last revised: August 23, 2018

Legal Notice

All information products included in http://ics-cert.us-cert.gov are provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained within. DHS does not endorse any commercial product or service, referenced in this product or otherwise. Further dissemination of this product is governed by the Traffic Light Protocol (TLP) marking in the header. For more information about TLP, see http://www.us-cert.gov/tlp/.



SUMMARY

In May of 2011, security researcher Dillon Beresford of NSS Labs1 reported multiple vulnerabilities to ICS-CERT that affect the Siemens Simatic S7-1200 micro programmable logic controller (PLC). ICS-CERT and Siemens have confirmed that these vulnerabilities could allow an attacker with automation network access to execute various unauthorized commands against the S7-1200 PLC.

On June 10, 2011, Siemens released a Security Advisory and patch to address a portion of the reported vulnerabilities.

ICS-CERT has confirmed the effectiveness of this patch and continues to work with Siemens and Mr. Beresford on the other reported problems.

ICS-CERT is releasing this Alert to inform users of the available patch for the Siemens S7-1200 PLCs.

IMPACT

Successful exploitation of these vulnerabilities could result in the loss of process control, possibly precipitating damage to critical industrial control systems (ICSs).

MITIGATION

Where possible, ICS-CERT recommends that users of S7-1200 PLCs apply the patch developed by Siemens to help protect against exploitation of these vulnerabilities.

Siemens’ Security Advisory and patch are available at the following locations:

Advisory: http://support.automation.siemens.com/WW/llisapi.dll/csfetch/50428932/Siemens_Security_Advisory_SSA-625789.pdf

Patch: http://support.automation.siemens.com/WW/view/en/41886031/133100

For general information on the behavior of the Simatic S7-1200 in industrial networks, go to the following location: http://support.automation.siemens.com/WW/view/en/50428932.

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.

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

In addition to the patch, the following mitigations are recommended to reduce the risk of impact by the
reported vulnerabilities.

  • ICS-CERT and Siemens recommend that customers disable the embedded web server in TIA Portal Version 11 if it is not critical to operations.
  • ICS-CERT and Siemens recommend that customers apply a properly configured, strong password. The same password should not be reused across the automation network, where possible.
  • Apply defense-in-depth strategies for both enterprise and control system networks; see the ICS-CERT Recommended Practice document, Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
  • Restrict connections between the enterprise and control system networks, where possible.
  • Restrict remote access to enterprise and control system networks and diligently monitor any remote connections allowed; employ Virtual Private Network (VPN) connections for any remote system access.

FOLLOW-UP

ICS-CERT published a follow-up advisory titled ICSA-11-223-01 - Siemens SIMATIC PLCs Reported Issues Summary on the ICS-CERT Web page on August 21, 2011.


Contact Information

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

Email: NCCICCUSTOMERSERVICE@hq.dhs.gov
Toll Free: 1-888-282-0870

For industrial control systems cybersecurity information:  http://ics-cert.us-cert.gov 
or incident reporting:  https://ics-cert.us-cert.gov/Report-Incident?

The NCCIC continuously strives to improve its products and services. You can help by choosing one of the links below to provide feedback about this product.

Was this document helpful?  Yes  |  Somewhat  |  No

Back to Top