ABB System 800xA

1. EXECUTIVE SUMMARY

• CVSS v3 7.3
• ATTENTION: Low skill level to exploit
• Vendor: ABB
• Equipment: System 800xA
• Vulnerabilities: Incorrect Default Permissions

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow an attacker to escalate privileges, cause system functions to stop, and corrupt user applications.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following products of System 800xA are affected:

• OPC Server for AC 800M: Versions 6.0 and prior
• Control Builder M Professional: Versions 6.1 and prior
• MMS Server for AC 800M: Versions 6.1 and prior
• Base Software for SoftControl: Versions 6.1 and prior
• ABB System 800xA Base: Versions 6.1 and prior

3.2 VULNERABILITY OVERVIEW

3.2.1    INCORRECT DEFAULT PERMISSIONS CWE-276

Weak access control lists for system folders could allow low privileged users to modify system and application files.

CVE-2020-8472 has been assigned to this vulnerability. A CVSS v3 base score of 5.5 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

3.2.2    INCORRECT DEFAULT PERMISSIONS CWE-276

An attacker who successfully exploits the weak file permissions in one of the ABB System 800xA functions could corrupt applications by escalating privileges, executing arbitrary code, and affecting various engineering functions.

CVE-2020-8473 has been assigned to this vulnerability. A CVSS v3 base score of 7.3 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:R/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 these vulnerabilities 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.

The vulnerabilities in the OPC Server for AC 800M was corrected in System 800xA 6.1

In the Control Builder M Professional, MMS Server for AC 800M and Base Software for SoftControl and ABB System 800xA Base, the vulnerabilities will be corrected in future releases of System 800xA. These vulnerabilities are planned to be corrected in the next release on the 6.0.3 LTS track following 6.0.3.3

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

For more information please refer to ABB’s Cybersecurity Advisory.

CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. 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 these vulnerabilities. These vulnerabilities are not exploitable remotely.

• ABB