ABB Cylon FLXeon 9.3.5 (variant.js) Unauthenticated System Information Disclosure

Exploit Details

Basic Information

Exploit Title ABB Cylon FLXeon 9.3.5 (variant.js) Unauthenticated System Information Disclosure
Exploit ID ZSL-2025-5937
Type zeroscience
Published 2025-05-21T00:00:00
Modified 2025-05-21T00:00:00

CVSS Information

CVSS Score 0.0
Severity NONE
Vector NONE

CVE Information

Exploit Description

Title: ABB Cylon FLXeon 9.3.5 (variant.js) Unauthenticated System Information Disclosure Advisory ID: ZSL-2025-5937 Type: Local/Remote…

Exploit Code

ABB Cylon FLXeon 9.3.5 (variant.js) Unauthenticated System Information Disclosure

Vendor: ABB Ltd.

Product web page: https://www.global.abb

Affected version: FLXeon Series (FBXi Series, FBTi Series, FBVi Series)

CBX Series (FLX Series)

CBT Series

CBV Series

Firmware: <=9.3.5

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.

Desc: The ABB Cylon FLXeon BACnet controller’s /api/variant endpoint exposes sensitive

system information, including the internal IP address, MAC address, device model, and

build type, without requiring authentication. The get() function gathers network

interface data using the os.networkInterfaces() API and returns it in the HTTP response,

potentially allowing unauthenticated clients to fingerprint internal infrastructure

and gain insight into the device’s network configuration and hardware characteristics.

Tested on: Linux Kernel 5.4.27

Linux Kernel 4.15.13

NodeJS/8.4.0

Express

Vulnerability discovered by Gjoko ‘LiquidWorm’ Krstic

@zeroscience

Advisory ID: ZSL-2025-5937

Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2025-5937.php

21.04.2024

$ cat project

P R O J E C T

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$ curl -k https://7.3.3.1/api/variant

{“ipaddr”:”192.168.1.10″,”mac”:”00:00:00:00:xx:xx”,”variant”:{“variant”:”CBXi”,”onboardIo”:true,”router”:true,”ser485-ports”:[[“mstp”,”ctlmbus”,”none”],[“ctlstat”,”none”]]}}

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