IO-Link is a standardized point-to-point protocol used in industrial automation to connect sensors, actuators, and other field devices to an IO-Link master. It carries process data, device parameters, and diagnostics over a simple wired link, helping plants manage equipment more efficiently and keep devices interchangeable across vendors.
In cyber security, IO-Link matters because the protocol often sits inside an OT gateway or master that bridges field devices to larger control networks. The protocol itself is not the main risk; the surrounding management interface, firmware, and network exposure usually are. Attackers may target web panels, authentication flaws, or command handling in the master to gain control, change device settings, or disrupt operations. Defenders should inventory IO-Link masters, restrict administrative access, segment OT networks, and patch firmware promptly.