ubus is OpenWrt’s internal message bus for inter-process communication and remote procedure calls. It lets router services exchange requests, return results, and trigger actions such as reading configuration, changing settings, or restarting components. In practice, ubus is often exposed through a JSON-RPC layer so web interfaces and management tools can call backend functions in a structured way.
In cyber security, ubus matters because it sits in the management plane: the trusted path for administrative actions. If access control is weak, an attacker already on the local network may invoke privileged functions without proper authentication or authorization, leading to password changes, configuration disclosure, or device manipulation. Defenders should treat ubus endpoints like any other sensitive admin interface, limiting reachability, enforcing strong authorization, and auditing which RPC methods are exposed. A secure ubus deployment helps keep convenience from becoming a control-plane shortcut for attackers.