Out Of Bounds Read in Adonisjs with Basic Auth

An Out Of Bounds Read occurs when an application reads memory beyond the intended buffer, potentially exposing sensitive data or causing crashes. In AdonisJS, this can arise when array or buffer indices are derived from user-controlled input without proper validation. When Basic Authentication is used, credentials are typically parsed from the Authorization header and may be forwarded into business logic that handles arrays, strings, or typed arrays. If the application uses the decoded credentials to index into a collection (e.g., an array of roles, tokens, or configuration entries) without verifying bounds, an attacker can supply crafted credentials that lead to an out-of-bounds read.

For example, imagine an AdonisJS route that relies on Basic Auth and then indexes into a list of permissions based on a numeric value extracted from the username portion of the credentials. If the value exceeds the list length, the runtime may read adjacent memory, potentially leaking internal data structures or configuration details. This becomes especially risky when the application uses zero-filled buffers for cryptographic operations or token handling and an attacker can indirectly influence buffer sizes via the auth-derived index.

During a black-box scan, middleBrick tests unauthenticated attack surfaces where possible. For endpoints protected by Basic Auth, it evaluates whether authentication inputs can propagate into index-based operations that lack bounds checking. The scanner checks for indicators such as unchecked numeric parsing from usernames or passwords, direct use of credential-derived values as array indices, and patterns where strings from auth headers are used in memory-sensitive operations. These checks help identify whether an out-of-bounds read path exists in the flow from authentication to data processing.

Using OpenAPI/Swagger spec analysis, middleBrick correlates the securitySchemes of type http with scheme: basic against runtime behavior to ensure that inputs from the Authorization header are not introducing unsafe index calculations. Real-world CVEs in similar frameworks have involved numeric IDs parsed from headers being used to index into arrays without validation, leading to information disclosure. The scanner flags missing length checks, improper type coercion, and missing guard clauses that could allow an attacker to move from authentication bypass to data exposure via out-of-bounds reads.

Because AdonisJS applications often centralize auth logic in middleware, it is critical to validate and sanitize any data derived from credentials before using it in array or buffer operations. Failing to do so can expose sensitive in-memory data and undermine the intended isolation between authenticated contexts. The scanner’s checks for input validation and property authorization are designed to surface these risks before they can be exploited in production.

To prevent Out Of Bounds Reads when using Basic Auth in AdonisJS, ensure that any data extracted from credentials is validated, bounded, and never used directly as an index without explicit checks. Below are concrete remediation patterns with syntactically correct examples.

1. Validate and constrain numeric values from credentials before using them as indices.

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

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

export default class AuthController {
  public async login({ request, auth, response }: HttpContextContract) {
    const { username, password } = request.validate({ schema: authSchema })
    // Do not use username directly as an index
    const safeIndex = Math.abs(hashCode(username)) % MAX_ROLES
    const role = roles[safeIndex]
    await auth.use('local').login({ username, password })
    return response.ok({ role })
  }
}

2. Avoid indexing into arrays or buffers using raw credential-derived values. Instead, map credentials to known safe keys using a lookup object.

const ROLE_MAP: Record = {
  alice: 'admin',
  bob: 'user',
  charlie: 'guest'
}

export default class SessionController {
  public async handle({ request, auth }: HttpContextContract) {
    const { username } = request.authUser
    const role = ROLE_MAP[username] || 'guest'
    // role is now safely bounded
    return { role }
  }
}

3. When using buffers for cryptographic operations, ensure lengths are fixed and inputs do not affect buffer sizing.

import crypto from 'crypto'

export default class TokenController {
  public async generate({ request }: HttpContextContract) {
    const { apiKey } = request.qs()
    const fixedSalt = Buffer.from('fixed_salt_value_12') // 12 bytes, fixed
    if (!apiKey || apiKey.length !== 16) {
      throw new Error('Invalid API key length')
    }
    const key = crypto.pbkdf2Sync(apiKey, fixedSalt, 1000, 32, 'sha256')
    // key length is always 32 bytes, no out-of-bounds risk from variable input
    return { key: key.toString('hex') }
  }
}

4. Enforce strict bounds checking when credentials influence control flow or data selection.

export default class ProfileController {
  public async show({ params, auth }: HttpContextContract) {
    const userId = parseInt(params.id, 10)
    if (!Number.isFinite(userId) || userId < 0 || userId >= MAX_USERS) {
      throw new Error('User ID out of bounds')
    }
    const profile = await Profile.find(userId)
    return profile
  }
}

These patterns ensure that data derived from Basic Auth does not introduce memory safety issues. By combining schema validation, bounded mappings, fixed-size buffers, and explicit range checks, you reduce the risk of out-of-bounds reads in AdonisJS applications.