How IAST Detects Vulnerabilities

IAST's unique positioning enables detection capabilities that neither SAST nor DAST can match. By observing actual data flow through applications, IAST can trace tainted data from entry points through all transformations to potential vulnerability points. This complete visibility eliminates the guesswork inherent in other approaches—IAST knows exactly how data is processed and whether security controls are properly applied.

Consider SQL injection detection. While SAST identifies potential injection points through pattern matching and DAST attempts to exploit them blindly, IAST watches the actual SQL queries being constructed. It sees user input entering the application, tracks it through any transformations or validations, and observes whether it's properly parameterized when reaching the database. This direct observation provides certainty about vulnerability existence and exploitability.

Runtime context enables IAST to identify complex vulnerabilities involving application state, configuration, and environment. IAST can detect race conditions by observing actual threading behavior, identify authentication bypasses by tracking session state, and find business logic flaws by understanding application workflows. This contextual awareness extends to framework-specific vulnerabilities where IAST understands how frameworks process requests and apply security controls.