A control cabinet is an enclosure that holds the electrical and control components for a machine or industrial system, such as PLCs, drives, power supplies, relays, terminals, and network gear. In operational technology, it is the physical center of control logic: if an attacker can reach the cabinet, they may be able to reset devices, change wiring, plug into service ports, or install rogue hardware.
This matters in cyber security because many industrial attacks begin with physical access to a cabinet or with poor protection around it. A cabinet may expose Ethernet, serial, USB, or maintenance connections, and those interfaces can be used to bypass normal authentication or to stage further compromise. Defenders reduce risk with locked enclosures, tamper-evident seals, segmented cabling, restricted service access, inventory checks, and alarms or cameras where appropriate. In practice, securing the control cabinet is part of securing the machine itself: physical control often determines whether the digital controls remain trustworthy.