A coolant distribution unit is the control subsystem in a liquid cooling loop that regulates coolant temperature, pressure, and flow. In data centers, it sits between the heat sources and the facility-side cooling plant, helping move heat away from chips safely and consistently.
CDUs matter in cyber security because cooling is now part of system availability. If a CDU is misconfigured, overloaded, or tampered with, servers may throttle, fail, or shut down to protect hardware. Attackers who gain access to building management or industrial control systems can target coolant controls as an indirect denial-of-service path. Defenders therefore monitor CDU telemetry, lock down management interfaces, and add alarms for abnormal temperature, pressure, and flow values. In practice, the CDU is a critical operational control point that keeps high-density compute running within safe thermal limits.