ABB EIBPORT

Summary

ABB disclosed a cross-site scripting (XSS) vulnerability (CVE-2021-22291) in EIBPORT V3 KNX building management systems affecting multiple hardware variants. The flaw enables attackers to steal session IDs and gain unauthorized access to devices, potentially allowing information disclosure and configuration changes. A firmware update to version 3.9.2 or later resolves the issue; exploitation requires network access, though some customers have misconfigured systems to be internet-accessible.

Full text

ICS Advisory ABB EIBPORT Release DateMay 28, 2026 Alert CodeICSA-26-148-03 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. A firmware update is available that resolves these privately reported vulnerabilities in the product versions listed as affected in the advisory. An attacker who successfully exploited these vulnerabilities could access sensitive information stored inside the device and can change the configuration of the device. The following versions of ABB EIBPORT are affected: EIBPORT V3 KNX (2CLA963710W1001) <3.9.2 EIBPORT V3 KNX (2CSM256242R2001) <3.9.2 EIBPORT V3 KNX GSM (2CLA963720W1001) <3.9.2 CVSS Vendor Equipment Vulnerabilities v3 8 ABB ABB EIBPORT Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Background Critical Infrastructure Sectors: Critical Manufacturing, Information Technology Countries/Areas Deployed: Worldwide Company Headquarters Location: Switzerland Vulnerabilities Expand All + CVE-2021-22291 The vulnerability allows the successful attacker to receive a copy of the session id. View CVE Details Affected Products ABB EIBPORT Vendor:ABB Product Version:EIBPORT V3 KNX (2CLA963710W1001) Version <3.9.2, EIBPORT V3 KNX (2CSM256242R2001) Version <3.9.2, EIBPORT V3 KNX GSM (2CLA963720W1001) version < 3.9.2 Product Status:fixed, known_affected Remediations Vendor fixABB recommends that customers apply the update at the earliest convenience. Relevant CWE: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Metrics CVSS Version Base Score Base Severity Vector String 3.1 8 HIGH CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H Acknowledgments Psytester reported this vulnerability to ABB. Mitigating factors Recommended security practices and firewall configurations can help protect a process control network from attacks that originate from outside the network. Such practices include that process control systems are physically protected from direct access by unauthorized personnel, 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, and others that have to be evaluated case by case. Process control systems should not be used for Internet surfing, instant messaging, or receiving e-mails. Portable computers and removable storage media should be carefully scanned for viruses before they are connected to a control system. More information on recommended practices can be found in the documents listed in the Reference section. 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 hardware 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. Frequently asked questions What causes the vulnerability? The session management of vulnerable FW versions of EIBPORT, fails to maintain a secure session management. What is EIBPORT? EIBPORT is a building management system allowing to automate buildings based on the KNX standards. What might an attacker use the vulnerability to do? An attacker who successfully exploited these vulnerabilities can gain access to the EIBPORT device without authenticating her-, himself. Could the vulnerability be exploited remotely? No, recommended practices include that building automation 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. Following these best practices, an attacker cannot exploit the vulnerability remotely. Unfortunately, ABB became aware that some customers have commissioned EIBPORT not according to these best practices but have made the IP address to the device accessible over the Internet or other untrusted networks. ABB emphasizes that this configuration is against the intended use of the system. Can functional safety be affected by an exploit of this vulnerability? No. EIBPORT is not designed as a functional safety device. What does the update do? The update removes the vulnerabilities by modifying the way that the device firmware verifies login credentials and token or session identifiers. Furthermore, it hardens the product configuration wherever possible. When this security advisory was issued, had this vulnerability been publicly disclosed? No, ABB had not received any information indicating that this vulnerability had been exploited when this security advisory was originally issued. When this security advisory was issued, had ABB received any reports that this vulnerability was being exploited? No, ABB 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 9AKK108471A7808 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 advi

Indicators of Compromise

• cve — CVE-2021-22291

Entities