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.

Advisory (ICSA-18-067-02)

Siemens SIPROTEC 4, SIPROTEC Compact, and Reyrolle Devices using the EN100 Ethernet Communication Module Extension

Original release date: March 08, 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/.

CVSS v3 7.5

ATTENTION: Exploitable remotely/low skill level to exploit.

Vendor: Siemens

Equipment: SIPROTEC 4, SIPROTEC Compact, and Reyrolle devices using the EN100 Ethernet communication module extension

Vulnerability: Missing Authentication for Critical Function


Siemens reports that the vulnerability affects the following EN100 Ethernet module products:

  • EN100 Ethernet module IEC 61850 variant: All versions prior to V4.30,
  • EN100 Ethernet module PROFINET IO variant: All versions,
  • EN100 Ethernet module Modbus TCP variant: All versions,
  • EN100 Ethernet module DNP3 variant: All versions, and
  • EN100 Ethernet module IEC 104 variant: All versions.


Successful exploitation of this vulnerability could allow an attacker to either upgrade or downgrade the firmware of the device, including downgrading to older versions with known vulnerabilities.


For EN100 Ethernet module IEC 61850 variant (All versions prior to V4.30), Siemens recommends users update to V4.30, which can be located here:


All other affected products, Siemens has identified the following specific workarounds and mitigations that users can apply to reduce the risk. As a general security measure Siemens strongly recommends to protect network access with appropriate mechanisms (e.g., firewalls, segmentation, VPN). It is advised to configure the environment according to Siemens’ operational guidelines in order to run the devices in a protected IT environment.

Recommended security guidelines to Secure Substations and Defense-in-Depth can be found at:


For further inquiries on vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT:


For more information on this vulnerability and associated software updates, please see Siemens security notification SSA-845879 on their website:


NCCIC 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.

NCCIC reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

NCCIC 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.

Additional mitigation guidance and recommended practices are publicly available in the NCCIC Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT website.

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

No known public exploits specifically target this vulnerability.


Successful exploitation of this vulnerability could allow an attacker to either upgrade or downgrade the firmware of the device, including downgrading to older versions with known vulnerabilities.

CVE-2018-4838 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).


Ilya Karpov and Alexey Stennikov from Positive Technologies reported this vulnerability to Siemens.


Critical Infrastructure Sectors: Energy

Countries/Areas Deployed: Worldwide

Company Headquarters Location: Germany

Contact Information

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

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