CISSP: Certified Information Systems Security Professional

The CIA triad defines three core security principles: Confidentiality, Integrity, and Availability. Availability refers to ensuring that authorized users can access systems and data when needed. An account lockout policy that is too strict (e.g., locking accounts after only five failed attempts within ten minutes) can cause legitimate users to be frequently locked out, preventing them from accessing their accounts and resources. This is a direct impact on availability, since the control—intended to protect against unauthorized access—ends up denying access to authorized users as an unintended side effect.