ICS Advisory (ICSA-16-308-01)

Moxa OnCell Security Vulnerabilities

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Independent researcher Maxim Rupp has identified authorization bypass and disclosed OS commanding vulnerabilities in Moxa’s OnCell Security Software. Moxa has produced a new version to mitigate these vulnerabilities.

These vulnerabilities could be exploited remotely.


The following Moxa OnCell versions are affected:

  • OnCellG3470A-LTE,
  • AWK-1131A/3131A/4131A Series,
  • AWK-3191 Series,
  • AWK-5232/6232 Series,
  • AWK-1121/1127 Series,
  • WAC-1001 V2 Series,
  • WAC-2004 Series,
  • AWK-3121-M12-RTG Series,
  • AWK-3131-M12-RCC Series,
  • AWK-5232-M12-RCC Series,
  • TAP-6226 Series,
  • AWK-3121/4121 Series,
  • AWK-3131/4131 Series, and
  • AWK-5222/6222 Series.


An unauthorized user could download files by accessing a specific URL. An unauthenticated user is able to execute arbitrary command by web console.

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


Moxa is a Taiwan-based company that maintains offices in several countries around the world, including the US, UK, India, Germany, France, China, Russia, and Brazil.

The affected product, OnCell Security Software, is cellular IP gateways that can connect serial or Ethernet devices to a cellular network. According to Moxa, OnCell Security Software is deployed across several sectors including Commercial Facilities, Critical Manufacturing, Energy, and Transportation Systems. Moxa estimates that this product is used primarily in Asia and Europe.




Any user is able to download log files by accessing a specific URL.

CVE-2016-8362b has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).c


User is able to execute arbitrary OS commands on the server.

CVE-2016-8363e has been assigned to this vulnerability. A CVSS v3 base score of 9.1 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H).f



These vulnerabilities could be exploited remotely.


No known public exploits specifically target these vulnerabilities.


An attacker with a low skill would be able to exploit these vulnerabilities.


Moxa recommends that users disable HTTP/HTTPS after completing required configuration through web browser interface. Users can access via SNMP to enable HTTP/HTTPS if needed. If remote control or monitoring is required, users should enable “IP Protocol Filter” feature of OnCell/AWK products to prevent any unauthorized access to the administrative web management interface.

Moxa has developed the following patch plan.

Product Firmware Update Release Date
OnCellG3470A-LTE November 1, 2016
AWK-1131A/3131A/4131A Series November 1, 2016
AWK-3191 Series May 31, 2017
AWK-5232/6232 Series May 31, 2017
AWK-1121/1127 Series June 30, 2017
WAC-1001 V2 Series June 30, 2017
WAC-2004 Series June 30, 2017
AWK-3121-M12-RTG Series June 30, 2017
AWK-3131-M12-RCC Series June 30, 2017
AWK-5232-M12-RCC Series June 30, 2017

No future updates are planned for the following models:

  • TAP-6226 Series,
  • AWK-3121/4121 Series,
  • AWK-3131/4131 Series, and
  • AWK-5222/6222 Series.

Users should contact Moxa if further assistance is needed for these models at:


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-287: Improper Authentication, https://cwe.mitre.org/data/definitions/287.html, web site last accessed November 03, 2016.
  • bNVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8362, 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:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N, web site last accessed November 03, 2016.
  • dCWE-264: Permissions, Privileges, and Access Controls, https://cwe.mitre.org/data/definitions/264.html, web site last accessed November 03, 2016.
  • eNVD, https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8363, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory.
  • fCVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H, web site last accessed November 03, 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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