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Advisory (ICSA-15-246-03)

Moxa Industrial Managed Switch Vulnerabilities

Original release date: September 03, 2015 | Last revised: August 27, 2018

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Erwin Paternotte of Applied Riska has identified vulnerabilities in the Moxa EDS-405A/EDS-408A series managed Ethernet switches. Moxa has produced a firmware update to mitigate these vulnerabilities.

These vulnerabilities could be exploited remotely.


The following Moxa switches are affected:

  • Moxa EDS-405A/EDS-408A series managed Ethernet switches firmware Version V3.4 build 14031419 and prior.


An authenticated remote attacker could compromise the availability, integrity, and confidentiality of a Moxa industrial managed switch, including connected industrial assets.

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 EDS-405A/408A series are entry Level 5 and 8-port managed Ethernet switches designed especially for industrial applications. The switches support a variety of useful management functions, such as Turbo Ring, Turbo Chain, ring coupling, port-based VLAN, QoS, RMON, bandwidth management, port mirroring, and warning by email or relay. According to Moxa, these switches are deployed across several sectors, including Chemical, Commercial Facilities, Critical Manufacturing, Emergency Services, Energy, Food and Agriculture, Government Facilities, Water and Wastewater Systems, and others. Moxa estimates that these products are used globally but concentrated in the US, Europe, Chile, Argentina, Peru, Columbia, and Taiwan, with 50 to 60 percent of all sales in the US.




A privilege escalation vulnerability has been found in the administrative web interface of the Moxa industrial Ethernet switches. A user level account has by default read only access to the web interface. The check that prevents a user level account from modifying settings in the administrative web interface could be easily circumvented, resulting in elevated access privileges.

CVE-2015-6464c has been assigned to this vulnerability. Applied Risk has calculated a CVSSv2 base score of 8.5 for this vulnerability; the CVSS vector string is (AV:N/AC:L/Au:S/C:N/I:C/A:C).d


The embedded GoAhead web server running on the Moxa Ethernet switches is vulnerable to a denial-of-service attack. A crafted URL sent by an authenticated user causes a reboot of the device.

CVE-2015-6465f has been assigned to this vulnerability. Applied Risk has calculated a CVSSv2 base score of 6.8 for this vulnerability; the CVSS vector string is (AV:N/AC:L/Au:S/C:N/I:N/A:C).g


A Cross-Site Scripting (XSS) vulnerability has been found in the administrative web interface of the Moxa industrial Ethernet switches. An input field of the administrative web interface lacks input validation, which could be abused to inject JavaScript code.

CVE-2015-6466i has been assigned to this vulnerability. Applied Risk has calculated a CVSSv2 base score of 4.3 for this vulnerability; the CVSS vector string is (AV:N/AC:M/Au:N/C:N/I:P/A:N).j



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 addressed the reported vulnerabilities by releasing a firmware update for the affected devices. The firmware updates are available at the following location on their web site:


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 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.

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?

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