Moxa Multiple ARM-Based Computers

1. EXECUTIVE SUMMARY

• CVSS v3 7.8
• ATTENTION: Low attack complexity 
• Vendor: Moxa 
• Equipment: ARM-Based Computers 
• Vulnerability: Privilege Escalation 

2. RISK EVALUATION

Successful exploitation of this vulnerability could provide an attacker with root privileges and total control of the system. 

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Moxa reports this vulnerability affects the following products and versions:  

• UC-8100A-ME-T System Image: Versions v1.0 to v1.6 
• UC-2100 System Image: Versions v1.0 to v1.12 
• UC-2100-W System Image: Versions v1.0 to v 1.12 
• UC-3100 System Image: Versions v1.0 to v1.6 
• UC-5100 System Image: Versions v1.0 to v1.4 
• UC-8100 System Image: Versions v3.0 to v3.5 
• UC-8100-ME-T System Image: Versions v3.0 and v3.1 
• UC-8200 System Image: v1.0 to v1.5 
• AIG-300 System Image: v1.0 to v1.4 
• UC-8410A with Debian 9 System Image: Versions v4.0.2 and v4.1.2 
• UC-8580 with Debian 9 System Image: Versions v2.0 and v2.1 
• UC-8540 with Debian 9 System Image: Versions v2.0 and v2.1 
• DA-662C-16-LX (GLB) System Image: Versions v1.0.2 to v1.1.2 

3.2 VULNERABILITY OVERVIEW

3.2.1 EXECUTION WITH UNNECESSARY PRIVILEGES CWE-250

The affected devices and versions of Moxa's ARM-based computers have an execution with unnecessary privileges vulnerability, which could allow an attacker with user-level privileges to gain root privileges. 

CVE-2022-3088 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). 

3.3 BACKGROUND

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

3.4 RESEARCHER

En Garde ICSRange research team reported this vulnerability to CISA. 

4. MITIGATIONS

Moxa developed updates to address this vulnerability. Users should follow the instructions in Moxa's security advisory to update their system image.  

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

• Ensure the least-privilege user principle is followed.
• Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls and isolate them from business networks.
• When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its connected devices.

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 at cisa.gov/ics. Several CISA products detailing cyber defense best 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 at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

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

No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely. 

• Moxa