How SAST Identifies Vulnerabilities

SAST excels at finding certain vulnerability categories that manifest in code patterns. SQL injection vulnerabilities appear when user input flows into database queries without proper sanitization. SAST traces these data flows from input sources to database sinks, flagging paths lacking appropriate validation or parameterization. Similarly, cross-site scripting (XSS) vulnerabilities are identified when user input reaches output functions without proper encoding.

Buffer overflow detection showcases SAST's strength in memory safety analysis. By analyzing array declarations, loop boundaries, and memory operations, SAST can identify potential buffer overflows before they cause crashes or enable code execution. This analysis includes tracking array sizes, validating index calculations, and ensuring proper bounds checking. Modern SAST tools can even identify subtle issues like off-by-one errors that human reviewers might miss.

Authentication and authorization flaws represent more complex vulnerabilities that advanced SAST tools address. These tools analyze authentication flows, session management, and access control implementations. They can identify missing authentication checks, weak password policies, insufficient session randomness, and authorization bypasses. By understanding application architecture and security control placement, SAST identifies gaps in security coverage.