System Hardening

System hardening is the process of reducing security vulnerabilities by removing unnecessary software, services, and system access points. The goal is to make a computer as secure as possible while preserving the functionality it needs to operate.

A "hardened" system typically includes only essential applications and enabled features. Unused programs, background services, network ports, and user accounts are disabled or removed. Security settings are strengthened by enabling a firewall, requiring strong passwords, applying software updates, and restricting administrative access.

System hardening may also involve changing default configurations that could be exploited. For example, an administrator may disable guest accounts, limit remote access, enforce multi-factor authentication, and enable auditing so login attempts and other system activity can be monitored. On servers, hardening often includes disabling unused protocols and limiting which processes can run.

NOTE: Depending on the focus, system hardening may also be called "operating system hardening" or "security hardening."