Coverage and Accuracy Analysis

Coverage and Accuracy Analysis

Coverage patterns differ significantly between approaches. DAST coverage depends on the scanner's ability to discover and test application interfaces. Modern scanners use sophisticated crawling, JavaScript analysis, and API discovery to maximize coverage. However, DAST can only test code it can reach and execute through external interfaces. Hidden functionality, complex workflows, or code requiring specific conditions might remain untested.

IAST coverage aligns with application test coverage. Any code executed during testing—whether through automated tests, manual QA, or actual usage—receives security analysis. This means IAST coverage directly correlates with overall test coverage. Organizations with comprehensive test suites achieve excellent security coverage through IAST. Those with limited testing see corresponding gaps in IAST coverage.

Accuracy represents IAST's greatest advantage. By observing actual vulnerability conditions rather than inferring them from external behavior, IAST virtually eliminates false positives. When IAST reports a vulnerability, it has observed the specific conditions that enable exploitation. DAST's inference-based approach occasionally generates false positives when applications exhibit suspicious but ultimately secure behaviors.