1. EXECUTIVE SUMMARY

  • CVSS v3 7.8
  • ATTENTION: Low skill level to exploit
  • Vendor: Delta Electronics 
  • Equipment: CNCSoft ScreenEditor
  • Vulnerability: Stack-based Buffer Overflow

2. RISK EVALUATION

Successful exploitation of this vulnerability may allow arbitrary code execution. 

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of CNCSoft ScreenEditor are affected:

  • CNCSoft ScreenEditor Versions 1.01.26 and prior

3.2 VULNERABILITY OVERVIEW

3.2.1    STACK-BASED BUFFER OVERFLOW CWE-121

A stack-based buffer overflow may exist when processing specially crafted project files, which may allow an attacker to execute arbitrary code. 

CVE-2020-27281 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been assigned; 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

Kimiya, working with Trend Micro Zero’s Day Initiative, reported this vulnerability to CISA.

4. MITIGATIONS

Delta Electronics has released an updated version of CNCSoft ScreenEditor, and recommends users install update v1.01.28 on all affected systems. 

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability.

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 us-cert.cisa.gov. 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 us-cert.cisa.gov 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.

CISA also recommends users take the following measures to protect themselves from social engineering attacks: 

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

Source:

https://us-cert.cisa.gov/ics/advisories/icsa-21-005-06