Title: ABB Cylon FLXeon 9.3.4 (timeConfig.js) Authenticated Root Remote Code Execution
Advisory ID: ZSL-2025-5910
Type: Local/Remote
Impact: System Access, DoS
Risk: (5/5)
Release Date: 02.02.2025

Summary

BACnet® Smart Building Controllers. ABB's BACnet portfolio features a series of BACnet® IP and BACnet MS/TP field controllers for ASPECT® and INTEGRA™ building management solutions. ABB BACnet controllers are designed for intelligent control of HVAC equipment such as central plant, boilers, chillers, cooling towers, heat pump systems, air handling units (constant volume, variable air volume, and multi-zone), rooftop units, electrical systems such as lighting control, variable frequency drives and metering.

The FLXeon Controller Series uses BACnet/IP standards to deliver unprecedented connectivity and open integration for your building automation systems. It's scalable, and modular, allowing you to control a diverse range of HVAC functions.

Description

The ABB Cylon FLXeon BACnet controller is vulnerable to authenticated remote root code execution via the /api/timeConfig endpoint. An attacker with valid credentials can inject arbitrary system commands by manipulating parameters such as tz, timeServerYN, and multiple timeDate fields. The vulnerability exists due to improper input validation in timeConfig.js, where user-supplied data is executed via ChildProcess.exec() without adequate sanitization.

Vendor

ABB Ltd. - https://www.global.abb

Affected Version

FLXeon Series (FBXi Series, FBTi Series, FBVi Series)
CBX Series (FLX Series)
CBT Series
CBV Series
Firmware: <=9.3.4

Tested On

Linux Kernel 5.4.27
Linux Kernel 4.15.13
NodeJS/8.4.0
Express

Vendor Status

[21.04.2024] Vulnerability discovered.
[22.04.2024] Vendor contacted.
[22.04.2024] Vendor responds.
[02.05.2024] Working with the vendor.
[20.01.2025] Vendor releases version 9.3.5 to address this issue.
[02.02.2025] Coordinated public security advisory released.

PoC

abb_flxeon_rce4.txt

Credits

Vulnerability discovered by Gjoko Krstic - <gjoko@zeroscience.mk>

References

[1] https://search.abb.com/library/Download.aspx?DocumentID=9AKK108470A5684&LanguageCode=en&DocumentPartId=PDF&Action=Launch
[2] https://www.cve.org/CVERecord?id=CVE-2024-48841
[3] https://packetstorm.news/files/id/188963/

Changelog

[02.02.2025] - Initial release
[03.02.2025] - Added reference [3]

Contact

Zero Science Lab

Web: https://www.zeroscience.mk
e-mail: lab@zeroscience.mk