Insecure Deserialization in Adonisjs with Basic Auth

Insecure deserialization occurs when an application processes untrusted data without validating its type or integrity after deserialization. In AdonisJS, this risk is amplified when endpoints that accept serialized payloads (e.g., JSON, MessagePack, or cookie-based sessions) also rely on Basic Authentication for access control. Basic Auth transmits a base64-encoded username:password pair in the Authorization header; while not inherently unsafe when used over TLS, it is static and non-revocable per request, making it unsuitable for authorization decisions alone. When combined with insecure deserialization, an attacker who intercepts or guesses a valid Basic Auth credential can craft malicious serialized objects that execute code or alter behavior during deserialization, such as through prototype pollution in Node.js or gadget chains in Java-like environments if AdonisJS integrates with backend services. For example, an authenticated request might include a serialized object in JSON that, when parsed by a vulnerable dependency (e.g., a legacy js-yaml loader using load instead of safeLoad), triggers remote code execution. The unauthenticated attack surface tested by middleBrick includes endpoints protected only by Basic Auth, where the scanner sends serialized probes to detect unsafe parsing and missing integrity checks. Because AdonisJS applications often expose RESTful routes that accept rich payloads, improper deserialization combined with weak authorization boundaries can lead to authentication bypass or server-side attacks. The scanner’s checks for Input Validation and Unsafe Consumption are designed to surface these risks by correlating runtime behavior with OpenAPI/Swagger specs, including $ref resolution for schemas that define expected object structures.

Remediation focuses on replacing static Basic Auth with scoped, revocable tokens and strict input validation. Do not rely on Basic Auth alone for authorization; treat it as a weak primary gate and enforce role-based checks within your application logic. For AdonisJS, use middleware to validate tokens or session state before deserializing any payload. Below are concrete code examples showing secure patterns.

1. Enforce TLS and Avoid Basic Auth for Sensitive Operations

Always use HTTPS to protect credentials in transit. If you must accept Basic Auth for compatibility, validate and scope it tightly.

// config/auth.ts
import { defineConfig } from '@ioc:AdonisJS/Addons/Auth'

export default defineConfig({
  guards: {
    basic: {
      driver: 'basic',
      authenticator: 'App/Authenticators/BasicAuthenticator',
    },
    api: {
      driver: 'api', // token-based guard
      authenticator: 'App/Authenticators/ApiAuthenticator',
    },
  },
})

2. Validate and Sanitize Inputs Before Deserialization

Use strict schema validation (e.g., Joi or Yup) on incoming JSON bodies and reject unexpected types. Avoid passing raw serialized data to deserializers.

// resources/validators/user.ts
import { schema } from '@ioc:AdonisJS/Core/Validator'

export const userSchema = schema.create({
  username: schema.string({}, [rules.alpha(), rules.minLength(3)]),
  preferences: schema.object({}, {
    theme: schema.enum(['light', 'dark']),
    notifications: schema.boolean(),
  }),
})

// controllers/UserController.ts
import { HttpContextContract } from '@ioc:AdonisJS/Core/HttpContext'
import userValidator from 'App/Validators/user'

export default class UsersController {
  public async update({ request, response }: HttpContextContract) {
    const payload = await request.validate({ schema: userValidator })
    // Safe to use payload.username and payload.preferences
    return response.ok({ updated: true })
  }
}

3. Use Token-Based Authentication Instead of Basic Auth for APIs

Replace Basic Auth with API tokens stored server-side or in secure HTTP-only cookies. This allows revocation and reduces exposure from intercepted credentials.

// controllers/AuthController.ts
import { HttpContextContract } from '@ioc:AdonisJS/Core/HttpContext'
import { schema } from '@ioc:AdonisJS/Core/Validator'

export default class AuthController {
  public async login({ request, auth, response }: HttpContextContract) {
    const email = request.input('email')
    const password = request.input('password')
    const token = await auth.attempt(email, password, { expiresIn: '7d' })

    return response.ok({ token })
  }

  public async logout({ auth, response }: HttpContextContract) {
    await auth.logout()
    return response.noContent()
  }
}

4. Isolate and Monitor Deserialization Paths

Ensure that any deserialization (e.g., for webhooks or file imports) uses safe libraries and rejects objects with executable gadgets. Audit dependencies for known vulnerabilities (e.g., CVE-2021-21342 for unsafe parsers) and keep them updated.