Definition
Interactive Application Security Testing, or IAST, is a security testing method that combines aspects of static and dynamic analysis to identify vulnerabilities within running applications. It operates by instrumenting the application's code during execution, allowing it to monitor data flow and detect security flaws in real time. This approach provides developers and security professionals with immediate feedback on potential weaknesses, enabling faster remediation. For example, IAST can pinpoint SQL injection vulnerabilities by observing how user input is processed and whether it is properly sanitized before being used in database queries. Unlike SAST which analyzes code without execution, or DAST which tests from the outside, IAST gains internal visibility during runtime. Understanding IAST is crucial for roles involved in secure software development and is covered on certifications like CompTIA Security+ and CySA+.