Certified Information Systems Security Professional (CISSP) Practice Exam 2026 – All-in-One Guide to Mastering Your Certification!

A whitelist in security serves a critical function by permitting only specified, known good resources and entities. This proactive measure is essential in mitigating risks, as it restricts access to only those that have been explicitly authorized. By employing whitelisting, an organization can enhance its security posture by ensuring that only vetted and trusted applications, websites, or IP addresses can interact with the system or network.

In contrast to strategies that focus on blocking malicious entities or behaviors, such as blacklisting, whitelisting fundamentally shifts the security paradigm by assuming that anything not on the list is potentially harmful. This approach helps to minimize the attack surface and reduces the chances of security breaches by excluding unapproved software or connections.

The other options focus on different aspects of security management or risk mitigation. Blocking unauthorized access relates to general access control practices; creating a list of high-risk users pertains to user management and threat assessment; and tracking system performance and availability involves system monitoring and operational metrics, none of which encapsulates the essence of what a whitelist is designed to do.