Contents
🔍 What is SAST?
Static Application Security Testing (SAST) is a white-box testing method that analyses source code, bytecode, or binary code to detect vulnerabilities — without executing the application.
It’s one of the earliest and most effective ways to “shift left” in secure development, helping developers catch security flaws during the coding phase.
🧠 How SAST Works
SAST tools parse and analyse the codebase to find:
- SQL injection flaws
- Cross-site scripting (XSS)
- Hardcoded secrets or credentials
- Insecure use of libraries
- Buffer overflows or memory corruption
- Logic errors or insecure patterns
🧰 SAST in the DevSecOps Pipeline
| Phase | Action |
|---|---|
| Code Commit | SAST runs automatically in CI tools (GitLab CI, GitHub Actions, Jenkins). |
| Pre-merge | Findings surface in pull requests to ensure no critical issues are introduced. |
| Developer IDEs | Many SAST tools offer plugins to give real-time feedback as you write code. |
🧪 Popular SAST Tools
| Tool | Language Support | Notes |
|---|---|---|
| SonarQube | Java, C#, JavaScript, more | Popular open-source/code quality tool. |
| Checkmarx | Wide range | Enterprise-grade, deep analysis. |
| Fortify Static Code Analyzer | Enterprise languages | Widely used in regulated industries. |
| Semgrep | Python, JS, Go, more | Lightweight, developer-friendly. |
| CodeQL (GitHub) | C/C++, JS, Java | Powerful semantic query-based analysis. |
✅ SAST vs DAST
| Feature | SAST | DAST |
|---|---|---|
| Type | Static (code-based) | Dynamic (runtime) |
| When | During development | Post-deployment/test |
| Access | Full code visibility | Black-box or HTTP-level only |
| Finds | Coding flaws, insecure patterns | Runtime issues, logic flaws, misconfigurations |
📌 Benefits of SAST
- Early vulnerability detection (“shift-left”)
- Helps enforce secure coding practices
- Integrates into modern CI/CD workflows
- Reduces cost of remediation
- Supports regulatory compliance (e.g. PCI DSS, ISO 27001)
⚠️ SAST Challenges
- High false positives without tuning
- Limited detection of runtime issues (use DAST or IAST to complement)
- May miss issues in third-party compiled libraries
- Requires secure development expertise to act on results effectively