Definition
System hardening is the process of securing a system by reducing its surface of vulnerability, which is often in conjunction with a related computer system. It involves removing unnecessary software, accounts, and services, and configuring the remaining components securely. This practice makes systems more resilient against cyberattacks by minimizing potential entry points for malicious actors. For instance, disabling unused ports and protocols on a server is a common hardening technique. Unlike patching, which addresses known vulnerabilities, hardening focuses on proactive security by minimizing the attack surface from the outset. This concept is fundamental in domains like CompTIA Security+ and CISSP.