Fix Improper Error Handling in Nitro

Nitro's default error behavior is a recon goldmine. If you're letting unhandled exceptions bubble up, you're likely leaking stack traces, filesystem paths, and internal dependency versions. In a production environment, verbose errors are information disclosure vulnerabilities. We mitigate this by intercepting the error lifecycle and returning sanitized, uniform responses.

The Vulnerable Pattern

export default defineEventHandler(async (event) => {
  try {
    const result = await db.query('SELECT * FROM users WHERE id = ' + getQuery(event).id);
    return result;
  } catch (err) {
    // VULNERABLE: Leaking raw error details and stack trace to the requester
    return {
      success: false,
      error: err.message,
      trace: err.stack
    };
  }
});

The Secure Implementation

To harden Nitro, stop returning raw error objects. Use the 'createError' utility from H3 to standardize responses. This ensures that in production, sensitive metadata is stripped. Additionally, implement a global error handler in '~/server/plugins/error.ts' or use the 'nitro.config.ts' error handling options to catch any edge cases that escape individual handlers. Always log the full trace to a secure internal sink (like Sentry or CloudWatch) while providing the client with a generic status message and a non-sensitive correlation ID.

import { createError } from 'h3';
export default defineEventHandler(async (event) => {
try {
const id = getQuery(event).id;
// Assume validation happens here
return await db.query(‘SELECT * FROM users WHERE id = ?’, [id]);
} catch (err) {
// LOG: Internal logging for debugging (not sent to client)
console.error([Internal Error] ${err.message});
// SECURE: Throwing a sanitized H3 error
throw createError({
  statusCode: 500,
  statusMessage: 'Internal Server Error',
  data: { message: 'An unexpected error occurred. Reference ID: ' + event.context.requestId }
});
}
});