What is security hardening?
Answer
Security hardening is the process of reducing the attack surface of a system by removing unnecessary software, services, users, and permissions, and configuring secure settings. The goal: minimize the number of possible entry points an attacker can use. Hardening steps: (1) Remove unused services: disable/uninstall any service not needed (each is a potential vulnerability). (2) Change defaults: default credentials, ports, settings. (3) Least privilege: minimal permissions for users and services. (4) Enable firewall: only allow required ports. (5) Patch all software. (6) Enable logging and monitoring. (7) Disable/remove unused user accounts. (8) Encrypt sensitive data. (9) Configure strong password/key policies. (10) Enable host-based IDS. Baseline hardening standards: CIS Benchmarks (Center for Internet Security) provide step-by-step guides for every major OS, cloud service, and application. Tools: OpenSCAP, Lynis (audit), Ansible/Chef/Puppet (automate).