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Vol. 1 · Ed. 2026
CyberGlossary
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Entry № 097

BACnet

Was ist BACnet?

BACnetA building-automation and HVAC protocol standardized as ASHRAE 135 / ISO 16484-5 — widely deployed in HVAC, lighting, fire-alarm, and access-control systems in commercial buildings, historically with very weak authentication.

BACnet (Building Automation and Control networks) is the dominant communications protocol in commercial building automation. It is standardized as ANSI/ASHRAE 135 and ISO 16484-5 and underlies HVAC, lighting, fire-alarm, energy-management, and access-control systems in office buildings, hospitals, schools, data centers, and large industrial campuses. BACnet defines a layered protocol with multiple data-link options (BACnet/IP over UDP/47808, BACnet MS/TP over RS-485, BACnet/SC over TLS, plus older Ethernet, ARCNET, and LonTalk variants) and an object-oriented model of services and objects (Analog Input/Output, Binary Input/Output, Schedule, Trend Log, etc.). Legacy BACnet/IP has essentially no authentication: any host on the BACnet network can issue Write Property requests, broadcast Who-Is and I-Am, or inject device-control messages. The newer BACnet Secure Connect (BACnet/SC, 2020) runs BACnet over TLS-secured WebSockets and is the recommended path forward. Real-world incidents (including a 2017 ransomware attack on a Finnish heating control system and the 2024 Lviv FrostyGoop case, conceptually similar) routinely abuse weak BACnet posture. Defensive practices include strict VLAN isolation of building-automation networks from IT and OT-NDR coverage tuned for BACnet anomalies.

● Beispiele

  1. 01

    A pen-tester maps a building's BACnet network with `Who-Is` discovery and demonstrates an unauthenticated `WriteProperty` overriding a chiller setpoint.

  2. 02

    A retrofit project migrates the building's BACnet/IP backbone to BACnet/SC over TLS, with mutual certificate authentication between controllers.

● Häufige Fragen

Was ist BACnet?

A building-automation and HVAC protocol standardized as ASHRAE 135 / ISO 16484-5 — widely deployed in HVAC, lighting, fire-alarm, and access-control systems in commercial buildings, historically with very weak authentication. Es gehört zur Kategorie OT / ICS / IoT der Cybersicherheit.

Was bedeutet BACnet?

A building-automation and HVAC protocol standardized as ASHRAE 135 / ISO 16484-5 — widely deployed in HVAC, lighting, fire-alarm, and access-control systems in commercial buildings, historically with very weak authentication.

Wie funktioniert BACnet?

BACnet (Building Automation and Control networks) is the dominant communications protocol in commercial building automation. It is standardized as ANSI/ASHRAE 135 and ISO 16484-5 and underlies HVAC, lighting, fire-alarm, energy-management, and access-control systems in office buildings, hospitals, schools, data centers, and large industrial campuses. BACnet defines a layered protocol with multiple data-link options (BACnet/IP over UDP/47808, BACnet MS/TP over RS-485, BACnet/SC over TLS, plus older Ethernet, ARCNET, and LonTalk variants) and an object-oriented model of services and objects (Analog Input/Output, Binary Input/Output, Schedule, Trend Log, etc.). Legacy BACnet/IP has essentially no authentication: any host on the BACnet network can issue Write Property requests, broadcast Who-Is and I-Am, or inject device-control messages. The newer BACnet Secure Connect (BACnet/SC, 2020) runs BACnet over TLS-secured WebSockets and is the recommended path forward. Real-world incidents (including a 2017 ransomware attack on a Finnish heating control system and the 2024 Lviv FrostyGoop case, conceptually similar) routinely abuse weak BACnet posture. Defensive practices include strict VLAN isolation of building-automation networks from IT and OT-NDR coverage tuned for BACnet anomalies.

Wie schützt man sich gegen BACnet?

Schutzmaßnahmen gegen BACnet kombinieren typischerweise technische Kontrollen und operative Praktiken, wie in der Definition oben beschrieben.

Welche anderen Bezeichnungen gibt es für BACnet?

Übliche alternative Bezeichnungen: ASHRAE 135, Building Automation Network.

● Verwandte Begriffe