System hardening involves securing a system by reducing its surface of vulnerability, which includes changing default credentials, disabling unnecessary services, and applying security patches.
Details:
* A. Password encryption: Secures passwords but does not address the issue of default credentials.
* B. System hardening: Comprehensive approach to securing the system, including changing default credentials.
* C. Multifactor authentication: Adds an additional layer of security but does not solve the problem of default credentials being enabled.
* D. Patch management: Ensures software is up-to-date but does not directly address default credentials.
References: System hardening is a fundamental practice in securing systems and preventing unauthorized access, as detailed in security best practices and guidelines.