ABB B&R Automation Studio

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Summary

ABB became aware of vulnerability in the product versions listed as affected in the advisory. An update is available that resolves a vulnerability. Successful exploitation of this vulnerability may enable an attacker to masquerade as a trusted party when B&R Automation Studio establishes a connection with a server via the ANSL over TLS or OPC-UA protocol.

The following versions of ABB B&R Automation Studio are affected:

• Automation Studio <6.5, 6.5 (CVE-2025-11043)

Background

• Critical Infrastructure Sectors: Critical Manufacturing
• Countries/Areas Deployed: Worldwide
• Company Headquarters Location: Switzerland

Vulnerabilities

Acknowledgments

• ABB PSIRT reported this vulnerability to CISA.

Notice

The information in this document is subject to change without notice, and should not be construed as a commitment by B&R. B&R provides no warranty, express or implied, including warranties of merchantability and fitness for a particular purpose, for the information contained in this document, and assumes no responsibility for any errors that may appear in this document. In no event shall B&R or any of its suppliers be liable for direct, indirect, special, incidental or conse-quential damages of any nature or kind arising from the use of this document, or from the use of any hardware or software described in this document, even if B&R or its suppliers have been advised of the possibility of such damages. This document and parts hereof must not be reproduced or copied without written permission from B&R, and the contents hereof must not be imparted to a third party nor used for any unauthorized purpose. All rights to registrations and trademarks reside with their respective owners.

Frequently Asked Questions

What causes the vulnerability? – The vulnerability is caused by insufficient validation mechanisms for server certificates in the ANSL over TLS and OPC-UA client implementations. What is B&R Automation Studio? – B&R Automation Studio is an environment for developing and executing automation solutions, ranging from control and motion technology to HMI, operation, and integrated safety technology. What might an attacker use the vulnerability to do? – An attacker who successfully exploited this vulnerability could spoof a trusted server, potentially leading to the disclosure of confidential information or the alteration of data during transit. How could an attacker exploit the vulnerability? – An attacker could attempt to exploit this vulnerability by generating a maliciously crafted server certificate and manipulating network routing or name resolution to redirect traffic through a compromised node under their control. This would require that the attacker has access to the system network, by connecting to the network either directly or through a wrongly configured or penetrated firewall, or that he installs malicious software on a system node or other-wise infects the network with malicious software. Recommended practices help mitigate such attacks, see section Miti-gating Factors above. Could the vulnerability be exploited remotely? – Yes, an attacker who has network access to an affected system node could exploit this vulnerability. Recommended practices include that process control systems are physically protected, have no direct connections to the Internet, and are separated from other networks by means of a firewall system that has a minimal number of ports exposed. What does the update do? – The update removes the vulnerability by modifying the way that the ANSL and OPC-UA clients are validating server certificates. When this security advisory was issued, had this vulnerability been publicly disclosed? – No, B&R discovered this vulnerability as a part of its own security analysis. When this security advisory was issued, had B&R received any reports that this vulnerability was being exploited? – No, B&R had not received any information indicating that this vulnerability had been exploited when this security advisory was originally issued

Legal Notice and Terms of Use

This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).

Recommended Practices

CISA recommends users take defensive measures to minimize the exploitation risk of these vulnerabilities.

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 more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most recent 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 on cisa.gov. 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.

CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov 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.

Advisory Conversion Disclaimer

This ICSA is a verbatim republication of ABB PSIRT SA25P004 from a direct conversion of the vendor’s Common Security Advisory Framework (CSAF) advisory. This is republished to CISA’s website as a means of increasing visibility and is provided “as-is” for informational purposes only. CISA is not responsible for the editorial or technical accuracy of republished advisories and provides no warranties of any kind regarding any information contained within this advisory. Further, CISA does not endorse any commercial product or service. Please contact ABB PSIRT directly for any questions regarding this advisory.

Revision History

• Initial Release Date: 2026-01-19

Legal Notice and Terms of Use

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