Moxa NPort 5210 5230 5232

1. EXECUTIVE SUMMARY

• CVSS v3 7.5
• ATTENTION: Exploitable remotely/low skill level to exploit
• Vendor: Moxa
• Equipment: NPort 5210, 5230, 5232
• Vulnerability: Resource Exhaustion

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow a remote attacker to send TCP SYN packages, causing a resource exhaustion condition that would cause the device to become unavailable.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of NPort, a serial network interface, are affected:

• NPort 5210, 5230, and 5232 Versions 2.9 build 17030709 and prior.

3.2 VULNERABILITY OVERVIEW

3.2.1    UNCONTROLLED RESOURCE CONSUMPTION ('RESOURCE EXHAUSTION') CWE-400

The amount of resources requested by a malicious actor are not restricted, allowing for a denial-of-service condition.

CVE-2018-10632 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing, Energy, and Transportation Systems
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Taiwan

3.4 RESEARCHER

Mikael Vingaard reported this vulnerability to NCCIC.

4. MITIGATIONS

Moxa recommends that users upgrade to the latest firmware version, which can be found at:

https://www.moxa.com/support/download.aspx?type=support&id=904

NCCIC recommends 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.

NCCIC reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

NCCIC 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 on the ICS-CERT website in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to NCCIC for tracking and correlation against other incidents.

No known public exploits specifically target this vulnerability.