ICS Alert (ICS-ALERT-17-341-01)


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NCCIC is aware of a public report of an improper authentication vulnerability affecting WAGO PFC200, a Programmable Logic Controller (PLC) device. According to this report, the vulnerability is exploitable by sending a TCP payload on the bound port. This report was released after attempted coordination with WAGO. NCCIC has notified the affected vendor of the report and has asked the vendor to confirm the vulnerability and identify mitigations. NCCIC is issuing this alert to provide notice of the report and identify baseline mitigations for reducing risks to these and other cybersecurity attacks.

The report included vulnerability details for the following vulnerability:

Vulnerability TypeRemotely ExploitableImpact
Improper AuthenticationYesDenial of Service/Possible Remote Code Execution

NCCIC is aware of reports of an improper authentication vulnerability discovered by SEC Consult. The vulnerability report expands on previous research on CODESYS products by Reid Wightman. An attacker may be able to trigger additional functions or crash the PLC by sending a malicious payload to the bound Port (2455 by default).

The WAGO FPC200 is a line of PLC devices based on CODESYS runtime. WAGO is based in Germany. According to WAGO, its products are deployed across several sectors, including Commercial Facilities, Critical Manufacturing, Energy, and Transportation Systems. WAGO estimates that these products are used worldwide.


NCCIC released the follow-up advisory titled ICSA-18-044-01 WAGO PFC200 Series on February 13, 2018, on the ICS-CERT website.


SEC Consult recommends that the affected devices not be connected directly to the Internet.  A thorough security review should be conducted before using the device in a production environment.

NCCIC is currently coordinating with the vendor and security researcher to identify additional mitigations.

NCCIC recommends, as quality assurance, that users test the devices in a test development environment that reflects their production environment prior to installation. In addition, users should:

  • Monitor traffic on the default bound Port (2455).
  • 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 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 taking defensive measures.

NCCIC also provides a control systems recommended practices page on the ICS-CERT web site. 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 NCCIC 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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