Dangling Dns in Adonisjs with Dynamodb

A dangling DNS record occurs when a DNS entry points to a resource that no longer exists or is misconfigured. In an AdonisJS application that uses Amazon DynamoDB, this can happen when environment variables or configuration files reference a hostname (such as a custom domain or load balancer alias) that resolves to an unintended or deprecated endpoint. If the application relies on hostname-based routing or certificate validation, the request may be forwarded to an unexpected service, potentially exposing internal endpoints or intercepting traffic.

DynamoDB does not expose a traditional network endpoint that can be dangling in the DNS sense; however, an application can construct requests using a misconfigured endpoint URL or region-specific base address. For example, if the AWS SDK is initialized with a custom hostname that no longer resolves correctly, the SDK may fall back to public endpoints or fail in a way that reveals information or causes inconsistent authorization checks. When combined with AdonisJS configuration that dynamically sets the AWS region or endpoint based on environment variables, a stale DNS entry can lead to requests being sent to an incorrect or unmanaged service boundary.

This situation becomes a security concern when the application uses unauthenticated or weakly authenticated calls to DynamoDB due to assumptions about network isolation. An attacker who can influence DNS resolution (for example, through a compromised internal DNS server or a public domain takeover) may redirect traffic to a malicious endpoint that mimics the expected service. If the AdonisJS application does not strictly validate the endpoint or region, it may inadvertently send sensitive data to the rogue service. The combination of AdonisJS configuration patterns that load AWS credentials and endpoint settings at runtime, with DynamoDB operations that assume a trusted control plane, increases the risk of insecure defaults or inconsistent authorization being applied across different environments.

To detect this scenario, middleBrick performs unauthenticated scans that include checks for exposed administrative interfaces, insecure endpoint resolution, and missing input validation on configuration values. The LLM/AI Security module specifically tests for system prompt leakage and prompt injection risks that could arise if an attacker can influence external service endpoints. Findings are mapped to the OWASP API Top 10 and include prioritized remediation guidance, helping teams ensure that endpoint configuration remains consistent and verifiable across development and production environments.

Remediation focuses on hardcoding or validating endpoint configuration, ensuring that AWS SDK initialization uses explicit region settings and secure credential management, and avoiding dynamic hostname resolution for critical operations. In AdonisJS, you should define AWS configuration in environment variables with strict validation and avoid constructing endpoint URLs from untrusted input.

Use the official AWS SDK for JavaScript with explicit configuration. The following example shows how to initialize a DynamoDB client in an AdonisJS service provider with fixed region and proper credential handling:

import { DynamoDB } from '@aws-sdk/client-dynamodb';
import { fromIni } from '@aws-sdk/credential-providers';

const region = process.env.AWS_REGION || 'us-east-1';
const endpoint = process.env.DYNAMODB_ENDPOINT;

const client = new DynamoDB({
  region,
  endpoint: endpoint ? `https://${endpoint}` : undefined,
  credentials: fromIni({
    profile: process.env.AWS_PROFILE || 'default',
  }),
});

export default client;

This approach ensures that the endpoint is only used if explicitly provided and that credentials are loaded from a controlled profile. If you do not need a custom endpoint, omit it entirely to rely on the AWS-managed service endpoint, which reduces the risk of DNS-based redirection.

Validate environment variables at application startup to prevent misconfiguration. In AdonisJS, you can use the schema validator to enforce that the region matches an allowed list and that the endpoint, if present, conforms to expected patterns:

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

const awsConfigSchema = schema.create({
  AWS_REGION: schema.string.optional({}, [
    schema.enum(['us-east-1', 'us-west-2', 'eu-west-1']),
  ]),
  DYNAMODB_ENDPOINT: schema.string.optional({}, [
    schema.ip(),
    schema.regex(/^([a-z0-9]([a-z0-9\-]*[a-z0-9])?\.)*[a-z0-9]([a-z0-9\-]*[a-z0-9])?$/),
  ]),
});

export default awsConfigSchema;

Additionally, implement runtime checks before performing sensitive DynamoDB operations to confirm that the client is configured with the expected region. This helps prevent accidental requests to incorrect endpoints if DNS or environment configuration changes:

const EXPECTED_REGION = 'us-east-1';

if (client.config.region !== EXPECTED_REGION) {
  throw new Error(`Unexpected AWS region: ${client.config.region}`);
}

For applications using the middleBrick Pro plan, continuous monitoring can be configured to alert on configuration drift or unexpected endpoint resolution, ensuring that DNS or environment changes do not introduce security gaps. The GitHub Action can enforce a security threshold on scans, failing builds if risky configurations are detected before deployment.