1. EXECUTIVE SUMMARY

  • CVSS v3 7.8
  • ATTENTION: Low skill level to exploit
  • Vendor: Delta Electronics
  • Equipment: Delta Industrial Automation CNCSoft ScreenEditor
  • Vulnerabilities: Stack-based Buffer Overflow, Out-of-bounds Read

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could cause buffer overflow conditions that may allow information disclosure, remote code execution, or crash the application.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of CNCSoft ScreenEditor, a user interface, are affected:

  • CNCSoft ScreenEditor v1.00.96 and prior

3.2 VULNERABILITY OVERVIEW

3.2.1    STACK-BASED BUFFER OVERFLOW CWE-121

Multiple stack-based buffer overflows can be exploited when a valid user opens a specially crafted, malicious input file.

CVE-2020-7002 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).

3.2.2    OUT-OF-BOUNDS READ CWE-125

An out-of-bounds read overflow can be exploited when a valid user opens a specially crafted, malicious input file due to the lack of validation.

CVE-2020-6976 has been assigned to this vulnerability. A CVSS v3 base score of 3.3 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N).

3.3 BACKGROUND

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

3.4 RESEARCHER

Natnael Samson (@NattiSamson) and kimiya, working with Trend Micro’s Zero Day Initiative, reported these vulnerabilities to CISA.

4. MITIGATIONS

Delta recommends the following:

  • Update to the latest version of CNCSoft v1.01.24 (with ScreenEditor v1.00.98).
  • Restrict the interaction with the application to trusted files.

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

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.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.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.

No known public exploits specifically target these vulnerabilities. These vulnerabilities are not exploitable remotely.

Source:

https://www.us-cert.gov/ics/advisories/icsa-20-077-01