Prevention of Authorization Bypass Attacks

checkPermission.ts

import { Request, Response, NextFunction } from 'express';

interface User {
  id: string;
  roles: string[];
}

function checkPermission(permission: string) {
  return (req: Request, res: Response, next: NextFunction) => {
    const user = req.user as User;
    if (user && user.roles.includes(permission)) {
      next();
    } else {
      res.status(403).json({ error: "Permission denied" });
    }
  };
}

app.get('/sensitive-data', checkPermission('view_sensitive_data'), (req: Request, res: Response) => {
  // Handle the request
});