ABB AbilityTM Zenon Remote Transport Vulnerability

Summary

ABB disclosed a HIGH severity vulnerability (CVE pending) in Ability Zenon versions 7.50–14 affecting the Remote Transport Service. The flaw enables attackers with network access to trigger unauthorized system reboots via the Reboot OS function without authentication (CWE-306). No active exploitation in the wild has been reported; mitigation includes network segmentation and disabling zensyssrv.exe when Remote Transport is unused.

Full text

ICS Advisory ABB Ability Zenon Remote Transport Vulnerability (Update A) Release DateMay 26, 2026 Alert CodeICSA-26-146-03 Related topics: Industrial Control System Vulnerabilities, Industrial Control Systems View CSAF Summary ABB is aware of vulnerabilities in the product versions listed as affected in the advisory. The vulnerability enables unauthorized access to the Reboot OS function within the Remote Transport Service, allowing an attacker to trigger a system reboot without the required authentication. This functionality initiates a system reboot on the target machine. However, remote exploitation of this vulnerability is not feasible unless the attacker has already gained access to the network where the affected ABB Ability Zenon system is deployed. At the time of writing, there is no evidence that this vulnerability is being actively exploited in the wild. The following versions of ABB Ability Zenon Remote Transport Vulnerability are affected: Ability Zenon >=7.50|<=14 CVSS Vendor Equipment Vulnerabilities v3 7.5 ABB ABB Ability Zenon Remote Transport Vulnerability Missing Authentication for Critical Function Background Critical Infrastructure Sectors: Chemical, Communications, Critical Manufacturing, Dams, Energy, Healthcare and Public Health, Information Technology, Water and Wastewater Countries/Areas Deployed: Worldwide Company Headquarters Location: Switzerland Vulnerabilities Expand All + CVE-2025-8754 In the default configuration of the ABB Zenon software platform, the zensyssrv.exe service is set to start automatically. To utilize the Remote Transport Service, users are required to configure a password beforehand. However, a security vulnerability has been identified that enables unauthorized attackers to bypass authentication mechanisms and remotely initiate a system reboot without proper authorization View CVE Details Affected Products ABB Ability Zenon Remote Transport Vulnerability Vendor:ABB Product Version:ABB Ability Zenon >=7.50|<=14 Product Status:known_affected Remediations Workaround• Restrict network access to systems with the ABB Zenon Software Platform installed. - Ensure that access to a system is restricted by implementing access controls to minimize the risk of unauthorized access. • Assess the necessity of the ABB Zenon Remote Transport functionality. - Ensure that if the Remote Transport functionality is not used, the zensyssrv.exe (ABB Zenon System Service) is stopped or terminated. The zensyssrv.exe can also be stopped or terminated after authorized use to prevent this vulnerability. Relevant CWE: CWE-306 Missing Authentication for Critical Function Metrics CVSS Version Base Score Base Severity Vector String 3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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 ABB. ABB 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 ABB or any of its suppliers be liable for direct, indirect, special, incidental or consequential damages of any nature or kind arising from the use of this document, or from the use of any hard-ware or software described in this document, even if ABB 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 ABB, 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. Work around • Restrict network access to systems with the ABB zenon Software Platform installed. - Ensure that access to a system is restricted by implementing access controls to minimize the risk of unauthorized access. • Assess the necessity of the ABB Zenon Remote Transport functionality. - Ensure that if the Remote Transport functionality is not used, the zensyssrv.exe (ABB Zenon System Service) is stopped or terminated. The zensyssrv.exe can also be stopped or terminated after authorized use to prevent this vulnerability. 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 2NGA002743 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: 2025-08-12 Date Revision Summary 2025-08-12 1 Initial version. 2026-05-22 2 Minor correction to the affected product version in the product tree. 2026-05-26 3 Initial CISA Republication of ABB PSIRT 2NGA002743 advisory 2026-05-28 4 CISA Republication update based on ABB PSIRT 2NGA002743 advisory. Removed "Trademark" abbreviation from the Ability product name in the title and throughout the advisory. Legal Notice and Terms of Use This product is provided subject to this Notification and this Privacy & Use policy. Vendor ABB Tags Sector: Chemical Sector, Communications Sector, Critical Manufacturing Sector, Dams Sector, Energy Sector, Healthcare and Public Health Sector, Information Technology Sector, Water and Wastewater Systems Topics: Industrial Control System Vulnerabilities, Industrial Control Systems Please share your thoughts We recently updated our anonymous product survey; we welcome your feedback. Related Advisories May 28, 2026 ICS Advisory | ICSA-26-148-02 Jinan USR IOT Technology Limited (PUSR) USR-W610 RS232/485 to Wi-Fi/Ethernet Converter May 28, 2026 ICS Advisory | ICSA-26-148-03 ABB EIBPORT May 28, 2026 ICS Advisory | ICSA-26-148-08 XCharge C6 May 28, 2026 ICS Ad

Indicators of Compromise

• malware — zensyssrv.exe

Entities