Zone Transfer in Adonisjs with Dynamodb

A zone transfer in the context of AdonisJS with DynamoDB typically refers to an insecure data exposure pattern where internal or administrative endpoints that manage zone-like data (for example, DNS-like routing tables, tenant boundaries, or record ownership) are accessible without proper authorization checks. Because AdonisJS applications often define routes and policies centrally, a misconfigured route or an overly permissive policy can allow an unauthenticated or low-privilege caller to enumerate or export data that should remain scoped to a specific zone or tenant.

When DynamoDB is used as the persistence layer, zone-transfer-like exposures arise from how data is modeled and accessed. DynamoDB does not provide native joins or schema-level constraints; access patterns are defined by primary key design. If an endpoint lists or exports items based on a non-partition-key attribute (such as a zone or tenant identifier) without enforcing strict ownership and authorization, it can inadvertently expose all items that share that attribute. For example, a route like GET /zones/:zoneId/resources that queries DynamoDB with a zoneId filter but omits policy validation can allow an attacker to iterate over zone IDs and retrieve data from adjacent zones, effectively performing a horizontal privilege escalation across data zones.

This combination is risky because AdonisJS route handling can inadvertently trust client-supplied identifiers. If input validation and policy checks are inconsistent—for example, validating presence but not ownership—then an authenticated user can modify the zone identifier in the request to access another tenant’s data. DynamoDB’s fast, low-latency responses can make such enumeration feasible at scale, especially if rate limiting is absent. The risk is compounded when OpenAPI specs are generated automatically and $ref resolution does not enforce strict authorization requirements across operations, allowing generated documentation to imply broader access than intended.

Consider an AdonisJS controller that queries DynamoDB using the AWS SDK:

import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
import { DynamoDBClient, QueryCommand } from '@aws-sdk/client-dynamodb'

export default class ResourcesController {
  private ddb = new DynamoDBClient({})

  public async index({ request, response }: HttpContextContract) {
    const zoneId = request.param('zoneId')
    // Missing authorization check: can the caller access zoneId?
    const cmd = new QueryCommand({
      TableName: process.env.DYNAMO_TABLE!,
      KeyConditionExpression: 'zoneId = :z',
      ExpressionAttributeValues: { ':z': { S: zoneId } }
    })
    const data = await this.ddb.send(cmd)
    return response.send(data.Items)
  }
}

If the route binding zoneId is not validated against an access policy that confirms the authenticated actor’s membership in that zone, an attacker can supply arbitrary zone IDs and perform a zone enumeration or data exfiltration across zones. This maps to common web API risks such as broken access control (OWASP API Top 10 A01:2023), and can be discovered by scanning tools that compare spec-defined authorization requirements against runtime behavior.

Remediation focuses on strict authorization tied to the data model, input validation, and runtime checks. The key principle is to enforce that every DynamoDB query is scoped not only by key attributes but also by the actor’s permissions, and that zone identifiers are never trusted from the request alone.

First, encode zone membership in the access pattern. Instead of allowing the client-supplied zoneId to directly drive the query, derive it from the authenticated actor’s record. For example, store the user’s allowed zones in a separate DynamoDB table or as a set in the user item, and perform a join-like client-side check:

import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
import { DynamoDBClient, GetItemCommand, QueryCommand } from '@aws-sdk/client-dynamodb'

export default class ResourcesController {
  private ddb = new DynamoDBClient({})

  public async index({ auth, request, response }: HttpContextContract) {
    const user = auth.getUserOrFail()
    const zoneId = request.param('zoneId')

    // Ensure the user is a member of the requested zone
    const userCmd = new GetItemCommand({
      TableName: process.env.USERS_TABLE!,
      Key: { userId: { S: user.id } }
    })
    const userData = await this.ddb.send(userCmd)
    if (!userData.Item || !userData.Item.zones?.SS?.includes(zoneId)) {
      return response.forbidden({ message: 'Access denied to zone' })
    }

    // Now query with the verified zoneId
    const cmd = new QueryCommand({
      TableName: process.env.DYNAMO_TABLE!,
      KeyConditionExpression: 'zoneId = :z AND begins_with(entityId, :e)',
      ExpressionAttributeValues: {
        ':z': { S: zoneId },
        ':e': { S: 'RES#' }
      }
    })
    const data = await this.ddb.send(cmd)
    return response.send(data.Items)
  }
}

This approach ensures that the zone ID used in the DynamoDB query is a subset of zones the actor is allowed to access, preventing zone traversal. It also demonstrates how to use begins_with to further constrain entity types within a zone, reducing the risk of accidental exposure of other items that share the same zone ID prefix.

Second, validate and sanitize all inputs. Use AdonisJS schema validation to ensure the zoneId conforms to expected patterns and reject unexpected formats before they reach DynamoDB:

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

const zoneResourceSchema = schema.create({
  zoneId: schema.string({ trim: true, escape: true }, [ rules.uuid() ]) // or rules.alphanumeric
})

export const validateZoneResource = async (ctx: HttpContextContract) => {
  await ctx.validate({ schema: zoneResourceSchema })
}

Third, apply consistent policy enforcement across all routes. Define a reusable policy that checks DynamoDB for zone-actor membership and apply it in route middleware:

import { BasePolicy } from '@ioc:Adonis/Core/Policy'
import { DynamoDBClient, GetItemCommand } from '@aws-sdk/client-dynamodb'

export default class ZonePolicy extends BasePolicy {
  public async canAccessZone(userId: string, zoneId: string) {
    const ddb = new DynamoDBClient({})
    const cmd = new GetItemCommand({
      TableName: process.env.USERS_TABLE!,
      Key: { userId: { S: userId } },
      ProjectionExpression: 'zones'
    })
    const res = await ddb.send(cmd)
    return res.Item?.zones?.SS?.includes(zoneId) ?? false
  }
}

Finally, ensure that the OpenAPI/Swagger spec accurately reflects required security schemes and that $ref resolution does not omit authorization requirements. Use explicit securitySchemes and require scope or role claims that align with zone permissions. With middleBrick’s OpenAPI/Swagger analysis, you can cross-reference spec definitions with runtime findings to detect mismatches where endpoints appear unauthenticated or underspecified in the spec but are enforced inconsistently at runtime.