BACnet (Building Automation and Control Networks) is a communication standard that lets products from different vendors exchange commands and status data in building systems. It is widely used for HVAC, lighting, access control, alarms, and other operational technology inside commercial buildings.
In cyber security, BACnet matters because it often bridges IT networks and physical control devices. If it is exposed, misconfigured, or left without strong access controls, an attacker may be able to discover devices, read operational data, spoof messages, or send unauthorized control commands. That can disrupt comfort, safety, or availability, and it can also reveal useful information about a site’s layout and operations.