Delta Electronics CNCSoft ScreenEditor

1. EXECUTIVE SUMMARY

• CVSS v3 7.8
• ATTENTION: Low attack complexity 
• Vendor: Delta Electronics 
• Equipment: CNCSoft  
• Vulnerability: Stack-based Buffer Overflow 

2. RISK EVALUATION

Successful exploitation of this vulnerability could cause a buffer overflow condition, which could allow remote code execution. 

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of CNCSoft, a software management platform, are affected: 

• CNCSoft: All versions prior to v1.01.34 
• Running ScreenEditor: All versions 1.01.5 and prior 

3.2 VULNERABILITY OVERVIEW

3.2.1 STACK-BASED BUFFER OVERFLOW CWE-121 

All versions prior to Delta Electronic’s CNCSoft version 1.01.34 (running ScreenEditor versions 1.01.5 and prior) are vulnerable to a stack-based buffer overflow, which could allow an attacker to remotely execute arbitrary code. 

CVE-2022-4634 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:N/UI:R/S:U/C:H/I:H/A:H). 

3.3 BACKGROUND

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

3.4 RESEARCHER

Simon Humbert, working with Trend Micro Zero Day Initiative, reported this vulnerability to CISA. 

4. MITIGATIONS

Delta Electronics released an updated version of CNCSoft and recommends users update to v1.01.34 or later. 

CISA 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 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. 

• Delta Electronics