SAST reliably flags well-known code patterns such as SQL injection, but it is weak on authentication, access control, insecure cryptography use and configuration problems. A clean SAST report means the patterns it knows were not found. It does not mean the application is secure.
Myth: a clean scan means no vulnerabilities
Fact: a scan reports what its rules and data flow analysis can recognise. OWASP's description of source code analysis tools says they find only a relatively small share of application security flaws. They are good at specific classes of issues and silent on the rest.
That does not make the tool useless. It means the report is evidence about some risks, not a certificate about all of them.
Myth: SAST finds access control bugs
Fact: broken access control depends on what your application is supposed to allow. The tool does not know that user A must not see user B's invoice. OWASP lists access control issues among the weak spots for automated static detection, and the testing guide stresses that serious problems are often tied to custom business logic that automated tools miss.
Catch these with design review, unit tests that assert authorization rules, and manual testing against the running application.
Myth: SAST handles configuration too
Fact: OWASP notes that static tools often miss configuration issues because those are not expressed in code. A permissive server setting or a missing header lives in deployment, not in source. Dynamic testing against a running application sees server configuration mistakes that source analysis cannot.
Myth: more rules means better coverage
Fact: more rules often means more noise. OWASP notes static tools produce many false positives and that it is hard to prove a reported issue is a real vulnerability. A rule set tuned to the frameworks you actually use usually beats a larger generic one.
Myth: SAST covers the open source you depend on
Fact: first party code analysis looks at the code you wrote. Vulnerabilities in third party packages are a different problem, handled by dependency scanning against known vulnerability data. Safeguard's SBOM and dependency scanning and reachability analysis address that side, and a free check is at gold.safeguard.sh/scan.
What covers each gap
A short mapping helps when planning a program:
- Business logic and authorization: design review, tests, manual testing.
- Configuration and runtime behavior: dynamic testing, deployment checks.
- Known weaknesses in dependencies: software composition scanning.
- Patterns in your own code: SAST.
No single column is enough, and none of them replaces the others.
Quick check
Does a SAST tool find hardcoded passwords?
Many tools have rules for obvious cases, but coverage varies. Ask a vendor to show detection on your own sample, and consider a dedicated secrets scanner as well.
If SAST misses so much, why use it?
It scales, runs on every change and points to the exact file and line for the issues it does catch. Cheap, early and repeatable is the value.
Sources
- Source code analysis tools, OWASP Community
- OWASP Web Security Testing Guide
- DAST, OWASP DevSecOps Guideline
- Free scan, Safeguard Gold
Last reviewed: 19 October 2026.
