ICS Advisory (ICSA-16-334-03)

Emerson DeltaV Wireless I/O Card Open SSH Port Vulnerability

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Emerson has identified an open SSH port vulnerability in the DeltaV Wireless I/O Card. Emerson has produced a firmware patch that disables the SSH port.

This vulnerability could be exploited remotely.


Emerson reports that the vulnerability affects the following products:

  • SE4801T0X Redundant Wireless I/O Card V13.3, and
  • SE4801T1X Simplex Wireless I/O Card V13.3

Note: The DeltaV system is not susceptible to this vulnerability except for the products and versions listed above.


An attacker may be able to use this open port to access the file system of devices using the affected product.

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


Emerson is a US-based company that maintains offices in several countries around the world, including the US, UK, Netherlands, Italy, India, Germany, France, Czech Republic, China, and Australia.

The affected products, DeltaV Wireless I/O Cards, are used to connect workstations and servers in the DeltaV network. According to Emerson, DeltaV Wireless I/O Cards are deployed across several sectors including Chemical and Energy. Emerson estimates that these products are used worldwide.




DeltaV Wireless I/O Cards (WIOC) running the firmware available in the DeltaV system, release v13.3, have the SSH (Secure Shell) functionality enabled unnecessarily.

CVE-2016-9347b has been assigned to this vulnerability. A CVSS v3 base score of 5.0 has been assigned; the CVSS vector string is (AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L).c



This vulnerability could be exploited remotely.


No known public exploits specifically target this vulnerability.


Crafting a working exploit for this vulnerability would be difficult.


Emerson released the solution for this vulnerability in their Guardian Support Knowledge Base Article NK-1500-0152 dated September 30, 2016 (hotfix bundle ‘DeltaV_133_WIOC_02_CSS’). The provided fix disables the SSH port that is always available in the WIOC running v13.3 original firmware.

In order to limit exposure to these and other vulnerabilities, Emerson recommends that users deploy and configure DeltaV systems and related components as described in the following documents:

  • DeltaV Security Manual


  • Emerson’s Wireless Security Whitepaper


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 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.

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

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.

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

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-306: Missing Authentication for Critical Function, https://cwe.mitre.org/data/definitions/306.html, web site last accessed November 29, 2016.
  • bNVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9347, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory.
  • cCVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L, web site last accessed November 29, 2016.

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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