Http Request Smuggling in Adonisjs with Dynamodb

HTTP request smuggling arises when an API processes HTTP requests in a way that allows an attacker to smuggle a malicious request between two backend interpretations. In an AdonisJS application that uses DynamoDB as the primary data store, the risk is introduced at the boundaries where AdonisJS parses and forwards requests—especially when the app sits behind a load balancer, reverse proxy, or API gateway that also parses HTTP.

AdonisJS does not inherently introduce smuggling; the risk comes from mismatched parsing behaviors between the framework and the infrastructure. For example, AdonisJS relies on the Node.js HTTP parser, while proxies may use their own parsing logic. If an attacker sends a request with conflicting Content-Length and Transfer-Encoding headers, and the proxy processes one while AdonisJS processes another, the request can be split or misinterpreted. Because DynamoDB operations in AdonisJS often involve deserializing JSON bodies and constructing low-level parameters (e.g., for GetItem or PutItem), a smuggled request can cause the backend to execute unintended database actions or bypass expected input validation.

This is particularly relevant when the application exposes endpoints that accept raw request bodies and forward them to DynamoDB without strict schema validation. For instance, an endpoint that accepts a JSON payload to create a record might be tricked into processing an additional request—such as updating an admin user or reading another user’s data—because the smuggling alters how headers are parsed before the request reaches AdonisJS controllers. Attack patterns like request splitting, request injection, and response splitting can manipulate the effective request that reaches DynamoDB, leading to unauthorized data access or mutation.

To detect this, scanning tools check whether the API correctly handles ambiguous or conflicting HTTP headers and whether responses are dependent on header parsing order. Because DynamoDB integrations often assume trusted internal logic, overlooked header handling can lead to privilege escalation or data exposure despite the database’s own access controls.

Remediation focuses on ensuring AdonisJS enforces strict HTTP parsing before any DynamoDB interaction. Always validate and normalize headers in middleware, and avoid passing raw request bodies directly to DynamoDB parameter builders. Below are concrete steps and code examples.

• Enforce a single header parsing strategy: Ensure AdonisJS is the sole interpreter of Content-Length and Transfer-Encoding. Reject requests that contain both.
• Validate and sanitize input before DynamoDB operations: Use Joi or Yup schemas to validate payloads, and explicitly map validated fields to DynamoDB attribute values.
• Use parameterized DynamoDB commands: Avoid string interpolation when building request parameters.

Example: Secure DynamoDB GetItem with validated input

import { schema } from '@ioc:Adonis/Core/Validator'
import { DynamoDBClient, GetItemCommand } from '@aws-sdk/client-dynamodb'
import { unmarshall } from '@aws-sdk/util-dynamodb'

const client = new DynamoDBClient({ region: 'us-east-1' })

const getItemSchema = schema.create({
  tableName: schema.string.optional(),
  key: schema.object({
    id: schema.string(),
  }),
})

export async function getItemSafe(params: any) {
  const validated = await schema.validate({ schema: getItemSchema, data: params })

  const command = new GetItemCommand({
    TableName: validated.tableName || 'Users',
    Key: {
      id: { S: validated.key.id },
    },
  })

  const response = await client.send(command)
  return response.Item ? unmarshall(response.Item) : null
}

Example: Secure DynamoDB PutItem with strict body parsing

import { schema } from '@ioc:Adonis/Core/Validator'
import { DynamoDBClient, PutItemCommand } from '@aws-sdk/client-dynamodb'
import { marshall } from '@aws-sdk/util-dynamodb'

const client = new DynamoDBClient({ region: 'us-east-1' })

const createUserSchema = schema.create({
  body: schema.object({
    id: schema.string(),
    email: schema.string.emailFormat(),
    role: schema.enum(['user', 'admin']),
  }),
})

export async function createUserSafe(ctx: any) {
  const validated = await schema.validate({ schema: createUserSchema, data: ctx.request.body() })

  const command = new PutItemCommand({
    TableName: 'Users',
    Item: marshall({
      id: validated.id,
      email: validated.email,
      role: validated.role,
    }),
  })

  await client.send(command)
  ctx.response.status = 201
  ctx.response.body = { message: 'User created' }
}

Middleware to reject smuggling attempts

Add an early middleware that checks for conflicting headers and terminates the request if smuggling indicators are present.

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

export default class SmugglingProtectionMiddleware {
  public async handle({ request, response, next }: HttpContextContract) {
    const hasTE = request.has('transfer-encoding')
    const hasCL = request.has('content-length')

    if (hasTE && hasCL) {
      response.status(400).send({ error: 'Conflicting Content-Length and Transfer-Encoding headers' })
      return
    }

    await next()
  }
}

Register the middleware globally or on routes that interact with DynamoDB. This ensures that malformed or ambiguous requests are rejected before they reach controllers or DynamoDB operations.