Summary
This vulnerability was privately reported relating to ABB’s implementation of the IEC 61850 communication stack for MMS client applications used in some Automation control system products. Note: IEC 61850 communication typically supports MMS and GOOSE protocols. Some ABB products support both, others only MMS (e.g. S+ Operations and PM 877). In any case, GOOSE communication is not impacted by this reported vulnerability. If an attacker gains access to a site’s IEC 61850 network, then exploiting this vulnerability will result in a device fault (PM 877, CI850 and CI868 modules) and will require a manual restart. If this attack is directed at a S+ Operations node running IEC 61850 connectivity, this will result in a crash in the IEC 61850 communication driver which, if continued a repeating basis, will also result in a denial-of-service situation. Note that this does not have an impact on the overall availability and functionality of the S+ Operations node, only the IEC 61850 communication function. The System 800xA IEC61850 Connect is not affected.
The following versions of ABB System 800xA, Symphony Plus IEC 61850 are affected:
- AC800M Product line (System 800xA) CI868
- Symphony Plus SD Series CI850
- Symphony Plus MR (Melody Rack) PM 877
- S+ Operations
- Firmware <=6.0.0303.0, <=6.1.0031.0 , <=6.1.1004.0 , <=6.1.1202.0 , <=6.2.0006.0 , 6.1.1-3, 7.0, A_0, A_1, A_2.003, A_3.005, A_4.001, B_0.005, C_0, >=3.10|<=3.52, 3.53, 3.3, 2.3, 2.2, 2.1, 3.4 ()
| CVSS | Vendor | Equipment | Vulnerabilities |
|---|---|---|---|
| v3 6.5 | ABB | ABB System 800xA, Symphony Plus IEC 61850 | Improper Validation of Specified Quantity in Input |
Background
- Critical Infrastructure Sectors: Chemical, Critical Manufacturing, Energy, Water and Wastewater
- Countries/Areas Deployed: Worldwide
- Company Headquarters Location: Switzerland
Vulnerabilities
CVE-2025-3756
A vulnerability exists in the command handling of the IEC 61850 communication stack included in the product revisions listed above. An attacker with access to IEC 61850 networks could exploit the vulnerability by using a specially crafted 61850 packet, forcing the communication interfaces of the PM 877, CI850 and CI868 modules into fault mode or causing unavailability of the S+ Operations 61850 connectivity, resulting in a denial-of-service situation. The System 800xA IEC61850 Connect is not affected. Note: This vulnerability does not impact on the overall availability and functionality of the S+ Operations node, only the 61850 communication function.
Affected Products
ABB System 800xA, Symphony Plus IEC 61850
Vendor:
ABB
Product Version:
Product Status:
fixed, known_affected
Relevant CWE: CWE-1284 Improper Validation of Specified Quantity in Input
Metrics
Acknowledgments
- Hitachi Energy reported this vulnerability to ABB Global.
- ABB Global 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 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 is the scope of the vulnerability? – An attacker having access to the IEC 61850 network can force the ABB hardware devices to go to ‘fault’ state by sending a specially crafted 61850 packet. This will result in a denial-of-service situation affecting the primary functionality of the listed devices and requiring a manual reset. In the same way this vulnerability can cause the unavailability of the S+ Operations 61850 connectivity, if continued on a repeating basis (but not the whole S+ Operations node). The System 800xA IEC61850 Connect is not affected. What causes the vulnerability? – The vulnerability is caused by a weakness in the message processing in the IEC 61850 communication stack. What is CI868? – CI868 is a module used in AC800M product line (System 800xA) for IEC 61850 communication. What is CI850? – CI868 is a module used in Symphony Plus SD Series product line for IEC 61850 communication. What is PM 877? – PM 877 is a controller used in Symphony Plus MR (Melody Rack) product line for IEC 61850 communication. What is S+ Operations? – S+ Operations is the Human Machine Interface for supervision and control of Symphony based control or SCADA systems. It is a module used in AC800M product line (System 800xA) for IEC 61850 communication. What might an attacker use the vulnerability to do? – An attacker with access to IEC 61850 networks could exploit the vulnerability by sending a specially crafted 61850 packet to the S+ products, forcing the Communication Interfaces to fault modes or causing unavailability of the S+ Operations 61850 connectivity, resulting in a denial-of-service situation. How could an attacker exploit the vulnerability? – An attacker could try to exploit the vulnerability by creating a specially crafted message and sending the message to an affected system node. 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 otherwise infects the net-work with malicious software. Recommended practices help mitigate such attacks, see section Mitigating Factors. 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. Can functional safety be affected by an exploit of this vulnerability? – Functional safety systems are not affected by these vulnerabilities. What does the update do? – The update removes the vulnerability by modifying the way that the IEC 61850 stack, used by the ABB Process Automation Products described above, manages 61850 incoming messages. When this security advisory was issued, had this vulnerability been publicly disclosed? – No, ABB received information about this vulnerability through responsible disclosure. 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 7PAA020125 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: 2026-04-13
| Date | Revision | Summary |
|---|---|---|
| 2026-04-13 | 1 | Initial version. |
| 2026-04-30 | 2 | Initial CISA Republication of ABB PSIRT 7PAA020125 advisory |