All information products included in https://us-cert.cisa.gov/ics are provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained within. DHS does not endorse any commercial product or service, referenced in this product or otherwise. Further dissemination of this product is governed by the Traffic Light Protocol (TLP) marking in the header. For more information about TLP, see https://us-cert.cisa.gov/tlp/.
1. EXECUTIVE SUMMARY
- CVSS v3 7.6
- ATTENTION: Low attack complexity
- Vendor: Moxa
- Equipment: UC Series
- Vulnerability: Improper Physical Access Control
2. RISK EVALUATION
Successful exploitation of this vulnerability could allow an attacker with physical access to take full control of the device using the console port.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following bootloader versions of Moxa UC Series, industrial internet-of-things (IIoT) gateway devices, are affected:
- UC-8580 Series: V1.1
- UC-8540 Series: V1.0 to V1.2
- UC-8410A Series: V2.2
- UC-8200 Series: V1.0 to V2.4
- UC-8100A-ME-T Series: V1.0 to V1.1
- UC-8100 Series: V1.2 to V1.3
- UC-5100 Series: V1.2
- UC-3100 Series: V1.2 to V2.0
- UC-2100 Series: V1.3 to V1.5
- UC-2100-W Series: V1.3 to V1.5
3.2 VULNERABILITY OVERVIEW
An attacker with physical access to the affected Moxa UC Series devices can initiate a restart of the device and gain access to its BIOS. Command line options can then be altered, allowing the attacker to access the terminal. From the terminal, the attacker can modify the device’s authentication files to create a new user and gain full access to the system.
- CRITICAL INFRASTRUCTURE SECTORS: Multiple Sectors
- COUNTRIES/AREAS DEPLOYED: Worldwide
- COMPANY HEADQUARTERS LOCATION: Taiwan
Casper Bladt of ICSrange.com research team reported this vulnerability to CISA.
Moxa has developed updates for all of the affected products to address this vulnerability. Moxa encourages users to contact Moxa Technical Support (login required) to obtain the update.
Users are encouraged to visit Moxa’s security advisory for more information.
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics 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 webpage on cisa.gov/ics 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 CISA for tracking and correlation against other incidents.
No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely.
For any questions related to this report, please contact the CISA at:
Toll Free: 1-888-282-0870
CISA continuously strives to improve its products and services. You can help by choosing one of the links below to provide feedback about this product.
Please share your thoughts.
We recently updated our anonymous product survey; we'd welcome your feedback.