Moxa EDR-G903 Secure Router Vulnerabilities (Update A)

OVERVIEW

This updated advisory is a follow-up to the original advisory titled ICSA-16-042-01 Moxa EDR‑G903 Secure Router Vulnerabilities that was published May 17, 2016, on the NCCIC/ICS-CERT web site.

Independent researcher Maxim Rupp has identified vulnerabilities in Moxa’s EDR‑G903 secure routers. Moxa has produced a new firmware version to mitigate these vulnerabilities.

These vulnerabilities could be exploited remotely.

AFFECTED PRODUCTS

The following Moxa Secure Routers are affected:

• EDR-G903 Versions V3.4.11 and older.

IMPACT

Successful exploitation of these vulnerabilities may allow a remote attacker to escalate privileges, initiate a denial-of-service condition, and execute arbitrary code.

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

BACKGROUND

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, Moxa EDR-G903 series, is an industrial virtual private network (VPN) server with firewall/NAT all-in-one secure router. It is designed for Ethernet security applications in sensitive remote control or monitoring networks, According to Moxa, these secure routers are deployed across several sectors, including, Commercial Facilities, Critical Manufacturing, Emergency Services, Energy, and others. Moxa estimates that these products are used globally but concentrated in the US, Europe, Chile, Argentina, Peru, Columbia, and Taiwan; 50 to 60 percent of all sales are in the US.

VULNERABILITY CHARACTERIZATION

VULNERABILITY OVERVIEW

By accessing a specific uniform resource locator (URL) on the web server, a malicious user is able to access configuration and log files.

CVE-2016-0875NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-0875, web site last accessed December 22, 2016. has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N, web site last accessed May 17, 2016.

Configuration files contain passwords in plaintext.

CVE-2016-0876NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-0876, web site last accessed December 22, 2016. has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N, web site last accessed May 17, 2016.

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Ping function is available to every user, which may cause a memory leak in the affected device.

CVE-2016-0877NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-0877, web site last accessed December 22, 2016. has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N, web site last accessed December 22, 2016.

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By sending malicious requests in the form of a ping twice, the device independently produces “Cold start.”

CVE-2016-0878NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-0878, web site last accessed December 22, 2016. has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N, web site last accessed May 17, 2016.

After using the import function of configuration or log files they are not deleted from server side, and any attacker is able to download them “without authenticating” by accessing a specific URL.

CVE-2016-0879NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-0879, web site last accessed December 22, 2016. has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N, web site last accessed December 22, 2016.

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VULNERABILITY DETAILS

EXPLOITABILITY

These vulnerabilities could be exploited remotely.

EXISTENCE OF EXPLOIT

No known public exploits specifically target these vulnerabilities.

DIFFICULTY

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

MITIGATION

Moxa has created firmware version v3.4.12, and it is available to users upon request.

https://www.moxa.com/en/support/support/technical-support

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 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.

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.