Input Validation — CompTIA CySA+ (CS0-003) Practice Questions
Input validation is the defensive practice of verifying that all data supplied by users or external systems conforms to expected type, length, format, and range before it is processed or stored by an application. It is a foundational control that mitigates a broad range of injection-class vulnerabilities including SQL injection, command injection, and cross-site scripting. CySA+ tests candidates on how the absence or inadequacy of input validation appears in vulnerability scan findings and penetration test reports, and how to recommend both server-side and client-side validation strategies as part of a defense-in-depth approach. Understanding input validation helps analysts evaluate the root cause of application vulnerabilities and advise development teams on secure coding practices.