Vulnerability Detection Mechanisms

SAST detection mechanisms operate on code representations rather than actual execution. Pattern-based detection identifies known vulnerable code constructs—SQL concatenation, unsafe deserialization, hardcoded credentials. Data flow analysis tracks information from sources (user inputs) to sinks (dangerous functions), identifying paths lacking proper validation. Control flow analysis ensures security checks aren't bypassed through alternative execution paths. Symbolic execution explores possible program states to identify edge cases leading to vulnerabilities.

IAST detection observes actual program execution, providing certainty about vulnerability conditions. When user input reaches a SQL query, IAST sees the actual query construction, knowing whether parameterization occurred. During authentication, IAST observes whether proper checks execute and sessions are securely managed. This runtime observation eliminates ambiguity—vulnerabilities are confirmed through actual behavior rather than inferred from code patterns.

The detection mechanisms' differences create complementary coverage. SAST identifies vulnerabilities in rarely executed code paths that testing might miss. IAST confirms whether potential vulnerabilities are actually exploitable in runtime configurations. SAST catches design flaws apparent in code structure. IAST identifies emergent vulnerabilities from component interactions. Together, they provide comprehensive vulnerability detection across the application lifecycle.