IAST (Interactive Application Security Testing)

Interactive Application Security Testing (IAST) combines elements of SAST and DAST by placing sensors (agents) within the running application that monitor code execution, data flow, and runtime behavior during normal use or testing. When a request triggers a potentially vulnerable code path, IAST can trace the exact flow from input to vulnerable function, dramatically reducing false positives.

IAST operates by instrumenting the application runtime (via agent libraries added to the application process), giving it visibility into both the external behavior (like DAST) and internal code execution (like SAST). This dual visibility allows it to identify vulnerabilities with high accuracy and pinpoint the exact source code location.

IAST is most effective when run alongside functional testing or QA processes, turning existing test suites into security assessments. However, it requires application modification (adding the agent), may affect performance, and can only find vulnerabilities in code paths that are actually exercised.

How APVISO tests for this: APVISO provides DAST-style external testing that pairs well with IAST. While IAST monitors internal application behavior during testing, APVISO's AI agents generate the intelligent, realistic traffic that triggers code paths IAST can analyze.