A command-line interface, or CLI, is a text-based way to use software by typing commands instead of clicking through menus. In security operations, CLIs are common for administration, automation, scripting, and remote management because they are fast, precise, and easy to repeat. Tools that run with elevated privileges often use a CLI to perform system-wide tasks such as installing packages, updating servers, or managing services.
CLI tools matter in cybersecurity because their trust level is often high: if a command or parameter is mishandled, the impact can reach the whole host. Attackers may target CLI utilities to abuse weak input handling, overwrite files, or escalate privileges. Defenders rely on CLIs for incident response, patching, and hardening, but they also monitor them closely because logs, scripts, and command history can reveal suspicious activity. In short, a CLI is both a powerful administrative channel and a sensitive attack surface.