Credential Stuffing in Adonisjs (Typescript)

Adonisjs is a Node.js framework built on Express that provides structure for building APIs and web applications. When developers use Typescript with Adonisjs, they gain static typing but also introduce specific patterns that can inadvertently facilitate credential stuffing attacks if authentication logic is not carefully implemented.

Credential stuffing occurs when attackers automate login attempts using lists of compromised credentials from previous breaches. Adonisjs does not include built-in protection against this threat, and when combined with Typescript's type safety, developers may incorrectly assume that type-checked code is inherently secure against such attacks.

In Adonisjs applications using Typescript, authentication is typically implemented through guards and providers. A common vulnerability arises when password validation logic does not enforce rate limiting or when session management does not track failed attempts. Attackers exploit this by submitting thousands of username/password combinations against the /login endpoint until they find a match.

Typescript interfaces in Adonisjs often define strict shapes for request objects and user credentials. While this prevents certain runtime errors, it can lead developers to overlook security considerations because the code compiles successfully. For example, an interface might define a UserCredentials type that is used across multiple endpoints without proper validation of input entropy or request frequency.

Additionally, Adonisjs supports middleware chaining that can be misconfigured. If rate limiting middleware is applied after the authentication guard rather than before it, attackers can flood the system with login attempts before any throttling occurs. Typescript's compile-time checks do not detect this architectural flaw, allowing it to persist in production.

Real-world incidents have shown that APIs built with Adonisjs and Typescript are susceptible to credential stuffing when using third-party authentication providers that do not implement adaptive authentication. Attackers leverage automated tools to test stolen credential sets against the API's login endpoint, often succeeding within minutes due to lack of protective measures.

The combination of Adonisjs's flexibility and Typescript's strict typing creates a false sense of security. Developers may implement complex validation schemas that are fully type-safe but still vulnerable to volume-based attacks if they do not incorporate proactive defenses like request throttling, behavioral analysis, or multi-factor authentication.

To mitigate credential stuffing in Adonisjs applications using Typescript, developers must implement explicit protections that go beyond type safety. The following example shows an incorrect implementation that lacks rate limiting and then demonstrates the corrected version with proper safeguards.

// Incorrect: No rate limiting, vulnerable to credential stuffing
import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'

class AuthController {
  public async login({ request, auth, response }: HttpContextContract) {
    const { email, password } = request.all()
    
    try {
      const token = await auth.use('api').attempt(email, password)
      return token
    } catch (error) {
      return response.status(401).json({ error: 'Invalid credentials' })
    }
  }
}

// Correct: Rate limiting applied before authentication
import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
import { HttpContext } from '@ioc:Adonis/Core/HttpContext'

class AuthController {
  public async login({ request, auth, response, session }: HttpContextContract) {
    const { email } = request.only(['email'])
    
    // Rate limiting middleware should be applied at the route level
    // But in code, we can track failed attempts per IP
    const ip = request.ip()
    const failedAttempts = session.get(`failed_${ip}`) || 0
    
    if (failedAttempts > 5) {
      return response.status(429).json({ error: 'Too many attempts' })
    }
    
    try {
      const token = await auth.use('api').attempt(email, request.password())
      session.put('user', email)
      return token
    } catch (error) {
      const newFailedAttempts = failedAttempts + 1
      session.put(`failed_${ip}`, newFailedAttempts)
      return response.status(401).json({ error: 'Invalid credentials' })
    }
  }
}

Additional remediation steps include enforcing strict password complexity requirements, implementing account lockout policies after repeated failures, and integrating with services that detect suspicious login patterns. Typescript interfaces should explicitly define authentication request shapes to ensure consistent validation across endpoints, preventing bypass through malformed inputs.

Developers should also consider using Adonisjs's built-in request validation combined with middleware that tracks request frequency. By defining a UserLogin interface that requires specific fields and applying validation rules that limit request rates, applications can significantly reduce exposure to credential stuffing attacks while maintaining type safety.