Broken Authentication in Restify with Mongodb

Broken Authentication occurs when application functions related to session management, credential verification, or token handling are implemented insecurely. The combination of Restify and Mongodb can introduce specific risks if authentication logic relies on unsafe query patterns, missing validations, or weak session handling.

In Restify, routes that accept user input for authentication (e.g., login or token verification) must avoid direct, unchecked use of that input in Mongodb queries. For example, constructing a query object by concatenating user-controlled values can bypass intended access controls or enable credential leakage. If a route does not enforce strong input validation and does not use parameterized queries, an attacker may manipulate the payload to alter query logic, such as injecting conditions that always evaluate to true.

Consider a login route that builds a Mongodb filter directly from request body fields without sanitization. If the filter is formed as an object where user input is mapped directly to fields, missing protections can allow an attacker to supply additional operators (e.g., $ne, $in) or nested conditions that change the authentication outcome. This can lead to authentication bypass, where an incorrect credential pair is accepted, or sensitive account enumeration via timing differences in query execution.

Session management in Restify must also guard against insecure storage or transmission of tokens. If JWTs or session identifiers are stored in insecure cookies, transmitted over non-encrypted channels, or validated without proper signature checks, the risk of token theft or tampering increases. Mongodb-backed token stores must ensure that token identifiers are indexed securely and that queries include explicit filters to prevent token guessing or over-privileged access. Without proper rate limiting and secure cookie attributes, the attack surface for token replay or brute-force grows significantly.

Additionally, excessive data exposure can occur when Mongodb queries return more fields than necessary during authentication workflows. Returning full user documents, including password hashes or sensitive metadata, increases the impact of a compromised endpoint. Restify handlers should explicitly project only required fields and ensure that error messages do not reveal whether a username exists, which helps mitigate enumeration attacks.

Compliance mappings such as OWASP API Top 10 (2023) A07:2021 – Identification and Authentication Failures, and relevant controls in SOC2 and GDPR, emphasize the need for secure authentication flows. middleBrick scans detect indicators of these risks in unauthenticated scans, highlighting missing input validation, unsafe query construction, and weak session handling patterns that can lead to authentication compromise.

To address Broken Authentication in Restify with Mongodb, apply strict input validation, use safe query construction, and enforce secure session handling. The following examples illustrate concrete, secure patterns.

1. Parameterized queries and strict filtering

Always construct Mongodb filters using explicit field names and avoid passing raw user input directly into query objects. Use validation libraries to sanitize and type-check credentials before building queries.

const restify = require('restify');
const { MongoClient } = require('mongodb');
const { body, validationResult } = require('express-validator');

const server = restify.createServer();
server.use(restify.plugins.bodyParser());

server.post('/login', [
  body('username').isString().trim().escape(),
  body('password').isLength({ min: 8 })
], async (req, res, next) => {
  const errors = validationResult(req);
  if (!errors.isEmpty()) {
    return res.send(400, { errors: errors.array() });
  }

  const client = new MongoClient('mongodb://localhost:27017');
  await client.connect();
  const db = client.db('myapp');
  const users = db.collection('users');

  // Safe: explicit field mapping, no user input concatenation
  const user = await users.findOne({
    username: req.body.username,
    // In practice, compare hashed passwords; this is illustrative
    passwordHash: req.body.passwordHash
  }, { projection: { username: 1, role: 1, passwordHash: 0 } });

  if (!user) {
    return res.send(401, { message: 'Invalid credentials' });
  }

  // Issue secure session token
  res.setHeader('Set-Cookie', `token=${generateToken(user); HttpOnly; Secure; SameSite=Strict}`);
  res.send(200, { role: user.role });
  return next();
});

2. Avoiding injection via query operators

Ensure user input cannot modify query semantics by rejecting keys that contain MongoDB operators. Validate that input fields do not contain unexpected dots or dollar signs that could be interpreted as operators.

function sanitizeFilter(input) {
  const forbiddenKeys = ['$', '.'];
  for (const key of Object.keys(input)) {
    if (forbiddenKeys.some(f => key.includes(f))) {
      throw new Error('Invalid filter key');
    }
  }
  return input;
}

const safeFilter = sanitizeFilter({
  username: req.body.username
});
const user = await users.findOne(safeFilter);

3. Secure token storage and verification

Store tokens with limited scope and verify them on each request using strong algorithms. Use HttpOnly, Secure cookies and include SameSite attributes to reduce exposure to cross-site attacks.

const jwt = require('jsonwebtoken');

function generateToken(user) {
  return jwt.sign(
    { sub: user._id, role: user.role },
    process.env.JWT_SECRET,
    { expiresIn: '1h', algorithm: 'HS256' }
  );
}

server.get('/profile', (req, res, next) => {
  const token = req.cookies.token;
  if (!token) {
    return res.send(401, { error: 'Missing token' });
  }
  try {
    const decoded = jwt.verify(token, process.env.JWT_SECRET);
    const user = usersCollection.findOne({ _id: decoded.sub }, { projection: { username: 1, role: 1 } });
    if (!user) {
      return res.send(401, { error: 'Invalid token' });
    }
    res.send(200, user);
  } catch (err) {
    return res.send(401, { error: 'Invalid token' });
  }
  return next();
});

4. Least privilege and token scope

Assign minimal scopes to tokens and validate them on resource access. In Mongodb, use role-based access control and ensure token verification checks both identity and permissions before allowing operations.

server.post('/action', (req, res, next) => {
  const token = req.cookies.token;
  const decoded = jwt.verify(token, process.env.JWT_SECRET);
  if (!decoded.scope || !decoded.scope.includes('action:execute')) {
    return res.send(403, { error: 'Insufficient scope' });
  }
  // Proceed with action
  res.send(200, { status: 'ok' });
  return next();
});

5. Continuous monitoring via middleBrick

Use the middleBrick CLI to scan your endpoints regularly and detect authentication misconfigurations. The Pro plan enables continuous monitoring and can integrate with GitHub Actions to fail builds when risk scores degrade, helping maintain secure authentication posture over time.