ICS Advisory

N-Tron 702W Hard-Coded SSH and HTTPS Encryption Keys (Update A)

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This updated advisory is a follow-up to the original advisory titled ICSA-15-160-01 N-Tron 702W Hard-Coded SSH and HTTPS Encryption Keys that was published June 9, 2015, on the NCCIC/ICS-CERT web site.

Independent researcher Neil Smith has identified hard-coded SSH and HTTPS encryption keys in N-Tron’s 702-W Industrial Wireless Access Point device. This vulnerability could allow an attacker to compromise communications and compromise the integrity of the device.

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Red Lion has been notified of this reported vulnerability and has produced a firmware update to mitigate this vulnerability. Neil Smith has tested the firmware update to validate that it resolves the vulnerability.

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This vulnerability can be exploited remotely.


The following N-Tron products are affected:

  • N-Tron 702-W Industrial Wireless Access Point, all versions.


The SSH and HTTPS private keys for secure communication can be copied from the device and the keys are the same on each device. Users do not have the ability to generate a new private key. These keys can be used to intercept communications from these devices to completely compromise the confidentiality and integrity of the transmitted data.

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


Spectris plc is a United Kingdom-based instrumentation and controls company that acquired N‑Tron on October 1, 2010, and is aligned closely with its Red Lion Controls subsidiary. In February 2013, Red Lion, Sixnet, and N-Tron were fully combined under the Red Lion Brand. N-Tron is a US-based company that maintains corporate offices in Mobile, Alabama, with representatives around the world, including Canada, China, India, Switzerland, and the United Kingdom.

According to the N-Tron web site, products are deployed across several sectors including Commercial Facilities; Energy; Nuclear Reactors, Materials, and Waste; Transportation Systems; and Water and Wastewater System, as well as other miscellaneous process control applications. N-Tron estimates that these products are distributed in over 50 countries worldwide.



HARD-CODED CRYPTOGRAPHIC KEYSCWE-321: Use of Hard-coded Cryptographic Key, http://cwe.mitre.org/data/definitions/321.html, web site last accessed June 09, 2015.

The SSH and HTTPS private keys used for secure traffic communication are hard-coded on the device and are not unique. An attacker can use these keys from one device to decrypt traffic from any other device. Users do not have the ability to generate new keys for the device. An attacker has the ability to use the key to completely compromise the confidentiality and integrity of the wireless traffic.

CVE-2012-4716NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2012-4716, web site last accessed September 24, 2015. has been assigned to this vulnerability. A CVSS v3 base score of 10.0 and a temporal score of 9.0 have been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N/E:P/RL:O/RC:C).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N/E:P/RL:O/RC:C, web site last accessed September 24, 2015.



This vulnerability can be exploited remotely as the keys can be pulled from firmware available from N-Tron.


No known public exploits specifically target this vulnerability.


An attacker with a low skill would be able to exploit this vulnerability.


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Red Lion has produced firmware update patch Version 2.0.24, which will allow the end user to upload unique keys/certificates to the unit (see pages 51-53 of the updated user manual). The updated user manual is available at the following location:http://www.redlion.net/product/702-w-industrial-wireless-radio

The updated firmware, Version 2.0.24, is available at the following location:http://www.redlion.net/resources/software/n-tron-software

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ICS-CERT recommends that 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.

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 at: http://ics-cert.us-cert.gov/content/recommended-practices. 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 (http://ics-cert.us-cert.gov/).

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.

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