1. EXECUTIVE SUMMARY

  • CVSS v3 7.8
  • ATTENTION: Low skill level to exploit
  • Vendor: ABB
  • Equipment: System 800xA Base
  • Vulnerability: Incorrect Permission Assignment for Critical Resource

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to escalate privileges and cause system functions to stop or malfunction.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of System 800xA Base are affected:

  • System 800xA Base: Versions 6.0 and prior

3.2 VULNERABILITY OVERVIEW

3.2.1    INCORRECT PERMISSION ASSIGNMENT FOR CRITICAL RESOURCE CWE-732

Low privileged users can read and modify registry settings used to control system functionality.

CVE-2020-8474 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: Chemical, Critical Manufacturing, Dams, Energy, Food and Agriculture, Water and Wastewater Systems
  • COUNTRIES/AREAS DEPLOYED: Worldwide
  • COMPANY HEADQUARTERS LOCATION: Switzerland

3.4 RESEARCHER

William Knowles of Applied Risk reported this vulnerability to ABB.

4. MITIGATIONS

ABB recommends changing any user account passwords suspected to be known by an unauthorized person. Interactive logon (both local and remote) is recommended to be disabled for the service account.

This vulnerability is corrected in System 800xA Base 6.1

This vulnerability is planned to be corrected in the next release on the 6.0.3 LTS track after 6.0.3.3

Please note this vulnerability can only be exploited by authenticated users, so users are recommended to ensure only authorized persons have access to user accounts in System 800xA.

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

  • Follow the principle of least privilege.

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 this vulnerability. This vulnerability is not exploitable remotely.

Source:

https://www.us-cert.gov/ics/advisories/icsa-20-154-02