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Shiva Charan
Shiva Charan

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🛡️ Dynamic Application Security Testing (DAST)

🔍 What is DAST?

  • Dynamic Application Security Testing (DAST) is a black-box security testing technique that analyzes a running application to identify security vulnerabilities from the outside, exactly like a real attacker would.

  • DAST tests the application behavior, not the source code.

  • Think of it as ethical hacking inside your CI/CD pipeline.

⚙️ Where DAST Fits in DevOps 

Code ➜ Build ➜ Test ➜ Deploy ➜ Run
                    🔍 DAST
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DAST is usually executed:

  • After deployment to staging
  • Sometimes in production (read-only scans)

🚀 How DAST Works (Simple Flow)

1️⃣ App is deployed and running
2️⃣ DAST tool sends malicious requests
3️⃣ App responds
4️⃣ Tool analyzes responses
5️⃣ Vulnerabilities are reported

🧠 No access to source code
🧠 No need to know the internal logic

🧪 What DAST Can Detect

✅ SQL Injection
✅ Cross-Site Scripting (XSS)
✅ Broken Authentication
✅ Insecure Cookies
✅ Open Redirects
✅ Security Misconfigurations

🟥 DAST finds what attackers exploit, not what developers write

❌ What DAST Cannot Do Well

❌ Logic flaws
❌ Dead code vulnerabilities
❌ Issues hidden behind complex auth
❌ Vulnerabilities that require source analysis

🆚 DAST vs SAST (Quick Comparison)

Feature 🧠 SAST 🌐 DAST
Tests Source code Running app
Access needed Yes No
Finds runtime issues ❌ ✅
Finds early bugs ✅ ❌
Attacker view ❌ ✅

👉 Best practice: Use both.

🔄 DAST in a CI/CD Pipeline 

DAST:
  stage: security
  script:
    - deploy_to_staging
    - run_dast_scan
    - fail_pipeline_on_critical
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✔ Automated
✔ Repeatable
✔ Enforced security gates

🧩 Real Example

🛒 Online Shopping App

  • App deployed to staging
  • DAST scan triggered automatically

  • Tool discovers:

    • /login vulnerable to SQL injection
    • Session cookie missing HttpOnly

  • Pipeline fails ❌

  • Developer fixes issue

  • Scan reruns

  • Pipeline passes ✅

🔥 Bug fixed before production exposure

🧰 Popular DAST Tools

🔹 OWASP ZAP
🔹 Burp Suite
🔹 Nikto
🔹 Acunetix
🔹 Netsparker

📈 Why DAST Matters in DevOps

🟢 Catches real-world attacks
🟢 Reduces breach risk
🟢 Improves compliance (PCI-DSS, ISO, SOC2)
🟢 Strengthens production confidence

⚠️ Without DAST, you ship code that only looks secure.

🧠 Best Practices

✔ Run DAST on every major release
✔ Scan authenticated endpoints
✔ Integrate with CI/CD
✔ Prioritize high & critical findings
✔ Combine with SAST + SCA

🧠 One-Line Summary

DAST tests your application the same way attackers do, but before they get the chance.

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