Best 7 Tips to Prevent IDOR Vulnerability in React.js (With Code)

🔐 Understanding Insecure Direct Object References (IDOR) in React.js

An Insecure Direct Object Reference (IDOR) is a type of access control flaw that occurs when an application exposes internal object references (like database record IDs or file paths) without proper validation. This allows attackers to manipulate input values to access unauthorized data.

While React.js is just a front-end JavaScript library, it often handles routing, data fetching, and rendering user-specific data. If developers don’t implement proper access controls on the backend, React can unintentionally expose sensitive data—opening the door to IDOR attacks.

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⚠️ Example of IDOR in React.js

// This React code fetches user data based on a userId stored in state or session
const userId = 105; // pulled from session or context
useEffect(() => {
  fetch(`/api/users/${userId}`)
    .then(response => response.json())
    .then(data => setUser(data));
}, []);

An attacker might intercept and modify this request (e.g., using DevTools or Burp Suite) to:

GET /api/users/106

If the backend doesn’t check whether the authenticated user owns or is authorized to access user 106, this leads to an IDOR vulnerability.

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📊 Real-World Impact of IDOR Vulnerabilities

IDOR vulnerabilities can be catastrophic. Here’s what they can lead to:

• Unauthorized access to user profiles
• Leaked sensitive data like emails, payment info, or documents
• Account takeover if tied to insecure session handling
• Legal and compliance violations (e.g., GDPR)

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📌 Screenshot: Webpage of Our Website Vulnerability Scanner Tools

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✅ 7 Best Practices to Prevent IDOR Vulnerability in React.js

1. Implement Access Control on the Server-Side

Never rely on React or the browser to enforce permissions.

Bad (Insecure):

<Route path="/admin/:id" component={AdminPage} />

Better (Secure):

// Backend (Node.js with Express)
app.get("/api/users/:id", authenticateToken, (req, res) => {
  if (req.user.id !== parseInt(req.params.id) && req.user.role !== "admin") {
    return res.status(403).json({ message: "Access denied" });
  }
  // Authorized
  getUserById(req.params.id).then(user => res.json(user));
});

Use middleware like authenticateToken() to validate JWTs or session cookies and always check ownership of the requested resource.

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2. Use UUIDs or Secure Object References

Predictable numeric IDs (/api/user/105) are easily enumerable. Use UUIDs instead.

// Secure API endpoint example
GET /api/user/550e8400-e29b-41d4-a716-446655440000

React Example:

useEffect(() => {
  fetch(`/api/user/${userUuid}`, {
    headers: {
      Authorization: `Bearer ${token}`
    }
  })
    .then(res => res.json())
    .then(data => setUser(data));
}, []);

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3. Avoid Using URL Params for Access-Controlled Data

Route-based access can be dangerous:

<Route path="/profile/:id" component={Profile} />

Instead, use token-authenticated endpoints:

fetch("/api/my-profile", {
  headers: {
    Authorization: `Bearer ${token}`,
  }
})

And on the backend:

app.get("/api/my-profile", authenticateToken, (req, res) => {
  User.findById(req.user.id).then(user => res.json(user));
});

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4. Add Role-Based Access Control (RBAC)

Not all users should have access to all resources. Enforce user roles:

if (req.user.role === 'admin' || req.user.id === data.ownerId) {
  res.json(data);
} else {
  res.status(403).json({ error: "Unauthorized access" });
}

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5. Log and Monitor Access Patterns

IDOR vulnerabilities can often be detected with unusual request patterns, like sequential access to /api/users/1, /api/users/2, etc.

Use logging tools (like Winston or Morgan) to record API access attempts and flag suspicious activity.

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6. Avoid Exposing Internal IDs in React Components

React developers often leak sensitive object IDs in components, like:

<button onClick={() => deleteFile(file.id)}>Delete</button>

If file.id is a database row ID, an attacker can intercept and reuse it. Instead, ensure the backend validates ownership and consider obfuscating or encrypting identifiers.

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7. Scan and Pen-Test Your App Regularly

You can detect and fix IDOR and many other vulnerabilities by scanning your app for Website Security checks regularly.

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🧪 Full Example: Secure Profile Management in React + Node.js

React Component:

useEffect(() => {
  fetch('/api/my-profile', {
    headers: {
      Authorization: `Bearer ${localStorage.getItem('token')}`
    }
  })
    .then(res => {
      if (!res.ok) throw new Error("Access Denied");
      return res.json();
    })
    .then(data => setProfile(data));
}, []);

Backend API:

app.get('/api/my-profile', authenticateToken, (req, res) => {
  User.findById(req.user.id)
    .then(user => res.json({ name: user.name, email: user.email }))
    .catch(err => res.status(500).send("Server Error"));
});

Token Middleware:

function authenticateToken(req, res, next) {
  const token = req.headers['authorization']?.split(' ')[1];
  if (!token) return res.sendStatus(401);

  jwt.verify(token, process.env.JWT_SECRET, (err, user) => {
    if (err) return res.sendStatus(403);
    req.user = user;
    next();
  });
}

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🧠 Further Reading: Strengthen Your Web App Security

• 🔗 5 Ways for CSRF Prevention in React.js
• 🔗 Prevent Session Replay Attack in TypeScript
• 🔗 Prevent Sensitive Data Exposure in RESTful APIs

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