Dns Rebinding in Adonisjs with Dynamodb

DNS rebinding is a network-based attack where an attacker causes a victim’s browser to resolve a domain name to an IP address that is not initially expected, often bypassing same-origin policy and network ACLs. In an AdonisJS application that interacts with Amazon DynamoDB, this can expose sensitive data or enable unauthorized operations when the client-side code or server-side logic makes assumptions about the origin or trustworthiness of requests.

Consider an AdonisJS backend that proxies requests to a DynamoDB endpoint based on client-supplied parameters, such as a table name or query parameters. If the application does not enforce strict origin checks and relies solely on IP-based or host-based validation, a malicious site can rebind the domain to an internal AWS endpoint or a compromised host serving a manipulated API. The attacker can craft a page that triggers authenticated requests from the victim’s browser to the AdonisJS server, which in turn issues signed DynamoDB requests using temporary credentials or IAM roles associated with the server.

DynamoDB-specific risks arise when the application uses long-lived AWS credentials or broad IAM policies on the server. For example, an AdonisJS route that calls DynamoDB.DocumentClient without validating the intended target against a strict allowlist may inadvertently allow a rebinding-induced request to scan tables or read sensitive items. Because the browser follows the rebind, the origin header may appear legitimate if the server does not validate the Origin or Referer headers. This can lead to unauthorized GetItem, Scan, or Query operations that expose PII or configuration data stored in DynamoDB.

In a black-box scenario, an attacker does not need to understand internal networking; they only need a vulnerable AdonisJS endpoint that makes unvalidated DynamoDB calls. middleBrick’s checks for Authentication, BOLA/IDOR, and Input Validation would flag missing origin verification and unsafe consumption patterns, while the LLM/AI Security probes ensure that no prompt or configuration leakage occurs via indirect channels introduced by rebinding-induced requests.

To mitigate DNS rebinding risks in an AdonisJS application that uses DynamoDB, enforce strict request validation, avoid relying on implicit trust, and design server-side calls to be idempotent and scoped.

Validate Origin and Host Headers

Always validate the Origin and Referer headers on sensitive routes. Maintain an allowlist of known origins and reject requests that do not match.

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

export default class ApiController {
  public async dynamoAction({ request, response }: HttpContextContract) {
    const allowedOrigins = ['https://app.yourdomain.com', 'https://admin.yourdomain.com']
    const origin = request.headers().origin
    if (!origin || !allowedOrigins.includes(origin)) {
      return response.unauthorized('Invalid origin')
    }

    // Proceed with DynamoDB logic
  }
}

Use Parameterized Queries and Strict Table Names

Do not concatenate user input into table names or key conditions. Use a mapping layer and strict validation to ensure only expected tables are accessed.

import { DynamoDBDocumentClient, GetCommand } from '@aws-sdk/lib-dynamodb'
import { ddbClient } from 'App/Services/DynamoDb'

const TABLE_MAP: Record = {
  user_profiles: process.env.USER_TABLE!,
  app_config: process.env.CONFIG_TABLE!,
}

export async function getItemSafe(tableKey: string, key: Record) {
  if (!TABLE_MAP[tableKey]) {
    throw new Error('Invalid table reference')
  }
  const client = DynamoDBDocumentClient.from(ddbClient)
  const command = new GetCommand({
    TableName: TABLE_MAP[tableKey],
    Key: key,
  })
  return await client.send(command)
}

Apply Least-Privilege IAM Roles

Ensure the AWS credentials or role used by AdonisJS have minimal permissions scoped to required DynamoDB actions and resources. Avoid broad dynamodb:* permissions.

# Example IAM policy snippet (not code, but guidance)
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "dynamodb:GetItem",
        "dynamodb:Query"
      ],
      "Resource": "arn:aws:dynamodb:region:account-id:table/user_profiles"
    }
  ]
}

Enable Request Throttling and Signature Validation

Use AdonisJS middleware to enforce rate limiting and verify that requests carry valid authentication signatures. This reduces the window for rebinding-based abuse.

import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
import { middleware } from '@ioc:Adonis/Addons/RateLimiter'

Route.group(() => {
  Route.get('/dynamo/profile/:id', async ({ params }: HttpContextContract) => {
    const safeId = validateId(params.id)
    return await getItemSafe('user_profiles', { PK: `USER#${safeId}` })
  }).middleware([middleware.throttle()])
}).prefix('api/v1')

Leverage middleBrick for Continuous Checks

Use the CLI to scan endpoints regularly: middlebrick scan <url>. The Pro plan enables continuous monitoring and CI/CD integration via the GitHub Action, which can fail builds if risk scores drop below your threshold. This helps catch regressions that could expose DynamoDB endpoints to rebinding or other API-specific attacks.