Injection is the one class all three testing types can find. Configuration problems are best seen by DAST, hardcoded secrets and risky code patterns by SAST, and runtime data flow by IAST. Access control and business logic flaws need manual testing in every case. Use this as a planning matrix.
The matrix in words
Injection. The OWASP Top 10 entry for injection says source code review is the best method of detecting it, and strongly encourages testing all inputs: parameters, headers, URLs, cookies, JSON, SOAP and XML. It adds that SAST, DAST and IAST tools can be added to the CI/CD pipeline to catch injection before production. This is the overlap zone. Pick whichever fits your workflow, and expect the combination to catch more than any one.
Server and deployment configuration. DAST is stronger here. The OWASP DevSecOps Guideline says DAST detects server configuration mistakes along with input and output validation and authentication problems. OWASP notes static tools often miss configuration issues since those are not expressed in code.
Hardcoded secrets and risky code patterns. SAST can point at the file and line. IAST sensors can also report items such as hardcoded API keys, per the guideline's examples. DAST, working from outside, would rarely see a key sitting in source.
Unsanitized input reaching a dangerous call. SAST traces this through code and IAST observes it at runtime. DAST infers it from responses.
Insecure transport such as connections without SSL. IAST lists this as an example finding. DAST can also observe transport from outside.
Authentication and access control. OWASP lists these as weak spots for automated static detection. DAST can probe some authentication behavior, but the scanner documentation says logical flaws like broken access control are not detected by automated scanning. Manual testing and authorization tests are the realistic answer.
Business logic. The testing guide says the most serious issues are often tied to custom business logic, which generic tools miss. Design review and manual testing again.
How to use the matrix
For each row, ask: do we have anything covering this today? Mark the gaps. If the largest gap is configuration, a staging DAST scan is a reasonable next step. If it is injection in code written by many hands, SAST on pull requests fits. If everything marked gap is access control, buy a manual test, not a scanner.
A warning about overlap
Overlap sounds wasteful, but it protects you against each method's blind spots. The cost is duplicate findings. Pick one place to triage so the same issue is not worked twice.
Quick check
Which single type covers the most?
None covers everything. Injection is the only class all three target. The rest depends on which flaws matter for your app.
Who finds broken access control?
Mostly people and tests. Automated scanners do not know your authorization rules.
Sources
- A03 Injection, OWASP Top 10 2021
- DAST, OWASP DevSecOps Guideline
- IAST, OWASP DevSecOps Guideline
- Source code analysis tools, OWASP Community
- OWASP Web Security Testing Guide
- Active scan documentation, ZAP project
Last reviewed: 19 October 2026.
