Memory Leak in Adonisjs with Basic Auth

A memory leak in an AdonisJS application using HTTP Basic Authentication can emerge from the interaction between the auth lifecycle and Node.js garbage collection. When Basic Auth is enabled, every request carries an Authorization: Basic <base64> header. If the application or its dependencies retain references to request-scoped objects—parsed credentials, raw headers, or user model instances—across asynchronous operations, those objects cannot be reclaimed, causing heap growth over time.

This is particularly risky when routes perform operations that indirectly hold state, such as attaching user data to the request context for later use or spawning long-lived async tasks. For example, attaching the full user object returned by an ORM query to request.authUser and then referencing it in unresolved promises or event emitters prevents the associated Buffer, parsed headers, and objects from being freed. Under sustained load, this pattern can increase memory consumption steadily, leading to higher latency and, in constrained environments, process restarts.

Because middleBrick scans the unauthenticated attack surface, it can detect indicators such as elevated memory usage patterns and missing cleanup routines without needing credentials. The scan evaluates the authentication mechanism and flags findings related to improper resource handling that can contribute to memory growth. These findings map to the BOLA/IDOR and Unsafe Consumption checks, which highlight risky data retention and missing cleanup logic. Developers should ensure that request-specific data is short-lived, avoid caching entire user objects in closures, and explicitly nullify references in async callbacks to allow garbage collection to reclaim memory between requests.

Additionally, large or unbounded request payloads combined with Basic Auth increase the surface for retained buffers. If body parsing middleware buffers the entire request stream into memory and the application holds references to those buffers, memory can accumulate, especially when connections linger due to slow clients. MiddleBrick’s checks for Input Validation and Rate Limiting help surface missing size limits and missing backpressure handling that can exacerbate memory retention in authenticated scenarios.

To mitigate memory leaks with Basic Auth in AdonisJS, adopt patterns that limit object lifetimes and avoid retaining references across asynchronous boundaries. Use lightweight credential extraction, avoid attaching large objects to the request, and clean up resources explicitly in hooks or middleware.

Example: Minimal Basic Auth handler without retaining state

import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
import { schema } from '@ioc:Adonis/Core/Validator'

const authSchema = schema.create({
  username: schema.string({}, [rules.email()]),
  password: schema.string({}, [rules.minLength(8)]),
})

export default class AuthController {
  public async login({ request, auth, response }: HttpContextContract) {
    // Validate input to avoid retaining large payloads
    const payload = request.validate({ schema: authSchema })

    // Use a scoped lookup and avoid attaching the full user object
    const user = await User.findBy('email', payload.username)
    if (!user || !user.verifyPassword(payload.password)) {
      return response.unauthorized()
    }

    // Issue a stateless session token instead of relying on session retention
    const token = auth.use('api').generate(user, { expiresIn: '2h' })

    // Explicitly release references
    user.merge({ password: undefined })
    return response.ok({ token })
  }
}

Example: Cleanup in an authentication hook

import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
import { HttpContextMiddlewareContract } from '@ioc:Adonis/Core/HttpContext'

export default class MemorySafeAuthHook implements HttpContextMiddlewareContract {
  public async handle(ctx: HttpContextContract, next: () => Promise) {
    try {
      await next()
    } finally {
      // Clear potentially large objects after response is sent
      ;(ctx as any)._internalUser = null
      ctx.response.hasCompleted = true
    }
  }
}

Example: Route definition with scoped usage

import Route from '@ioc:Adonis/Core/Route'

Route.group(() => {
  Route.get('/profile', async ({ auth, response }) => {
    // Fetch only necessary fields to reduce retained payload size
    const user = await auth.authenticate()
    const safeUser = { id: user.id, email: user.email }
    return response.ok(safeUser)
  }).middleware(['MemorySafeAuthHook'])
}).prefix('api/v1')

These examples focus on avoiding long-lived references, validating input sizes, and releasing objects promptly. Combine these practices with middleBrick’s CLI tool to scan from the terminal with middlebrick scan <url> and integrate the GitHub Action to add API security checks to your CI/CD pipeline, failing builds if risk scores drop below your chosen threshold. For continuous monitoring, the Pro plan provides configurable schedules and alerts to catch regressions early.