Day 7: BackendChallenges.com – The Frontend Security Checklist Devs Ignore

Why Frontend Security Matters?

You might think backend is where security lives.

But truth is—most backend breaches start in the frontend.

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🔐 Challenge #1: Fix Leaky Token Storage

Problem:

Your React app stores access tokens in localStorage.

Fix:

✅ Use HttpOnly secure cookies

❌ Never expose tokens to JS or extensions

💡 Bonus: Rotate tokens securely

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🔍 Challenge #2: Input Validation

Problem:

User input from forms is sent directly to APIs.

Fix:

✅ Validate input on frontend AND backend

✅ Escape special characters

✅ Use a schema validator like zod or yup

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🌍 Challenge #3: Lock Down CORS

Problem:

Your frontend is served from any origin.

Your API allows Access-Control-Allow-Origin: *

Fix:

✅ Only allow specific trusted origins

✅ Block credentials from being shared

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🛡️ Start fixing frontend risks before they hit your backend:

👉 Frontend Security Checklist