Security Misconfiguration in Adonisjs with Mutual Tls

Security misconfiguration in AdonisJS applications that expose Mutual TLS (mTLS) endpoints often arises from incomplete or inconsistent TLS settings, which can weaken authentication and enable unauthorized access. When mTLS is enabled, the server requests a client certificate during the TLS handshake. If AdonisJS does not properly validate the client certificate or does not enforce strict verification, an attacker can present a missing, expired, or untrusted certificate and still establish a connection.

AdonisJS relies on the underlying Node.js TLS module. A typical misconfiguration is providing an incomplete or incorrect CA chain, which prevents the server from verifying the client certificate’s signature. For example, using ca: [] or pointing to a file that does not contain the root and intermediate certificates breaks the trust chain. Additionally, failing to set requestCert: true and rejectUnauthorized: true disables client certificate validation, allowing unauthenticated clients to reach application routes that should be protected.

Another common misconfiguration is improper file permissions on certificate and key files. If the private key for the server or the client certificate is readable by non-privileged processes, an attacker who gains limited access to the host can steal credentials and impersonate services. Incorrect cipher suite configurations can also introduce risk by allowing weak protocols or deprecated ciphers that are vulnerable to known attacks.

Routing and middleware misconfiguration can compound these issues. If mTLS-protected routes are not explicitly guarded and rely on implicit trust, an attacker who successfully completes a handshake with a low-privilege certificate may perform privilege escalation or access administrative endpoints. Without logging and monitoring of failed handshake attempts, such misconfigurations can remain undetected, enabling reconnaissance and lateral movement within the API surface.

These vulnerabilities map to common weaknesses such as CWE-295 (Improper Certificate Validation) and CWE-285 (Improper Authorization). In the context of API security checks, missing or weak mTLS configuration can be flagged as issues in Authentication and Property Authorization, because the API fails to enforce strict identity proofing. For compliance frameworks, weak mTLS implementations may fail requirements in PCI-DSS and SOC2 related to secure communication and access control.

To remediate security misconfiguration in AdonisJS with Mutual TLS, enforce strict server-side TLS options and validate client certificates on every connection. Below are concrete, working examples using Node.js TLS options within an AdonisJS service provider.

First, configure the HTTPS server with mandatory client certificate verification. Ensure the CA certificate used to sign client certificates is provided, and reject connections that cannot prove possession of a trusted certificate.

const fs = require('fs')
const https = require('https')
const { Ignitor } = require('@adonisjs/ignitor')

new Ignitor(require('@adonisjs/fold'))
  .appRoot(__dirname)
  .httpsServer({
    key: fs.readFileSync('keys/server.key'),
    cert: fs.readFileSync('certs/server.crt'),
    ca: fs.readFileSync('certs/ca-chain.crt'),
    requestCert: true,
    rejectUnauthorized: true,
    minVersion: 'TLSv1.2',
    ciphers: [
      'TLS_AES_256_GCM_SHA384',
      'TLS_CHACHA20_POLY1305_SHA256',
      'TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384'
    ].join(':'),
    honorCipherOrder: true
  })
  .start((address) => {
    console.log(`HTTPS server with mTLS listening on ${address}`)
  })

Second, implement application-level verification within middleware to double-check the client certificate details after a successful TLS handshake. Extract the certificate from the socket and validate its fields (such as Common Name or SAN) against an allowlist or an internal directory service.

// start/hooks.ts
import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'

export const validateClientCertificate = async (ctx: HttpContextContract, next: () => Promise) => {
  const request = ctx.request
  // The certificate is attached by the TLS layer in production-like environments
  const clientCert = request.socket.getPeerCertificate()

  if (!clientCert || !clientCert.subject) {
    ctx.response.unauthorized('Client certificate required')
    return
  }

  const { commonName } = clientCert.subject
  const allowedSubjects = ['service-inventory', 'data-processor', 'monitoring']
  if (!allowedSubjects.includes(commonName)) {
    ctx.response.forbidden('Unauthorized client identity')
    return
  }

  await next()
}

Third, store certificates with strict file permissions and reference them using absolute paths in your configuration to avoid accidental exposure or misplacement. Rotate CA and client certificates on a defined schedule and monitor handshake failures to detect brute-force or probing attempts.

When integrating with the middleBrick ecosystem, you can use the CLI to scan your AdonisJS endpoints and verify that mTLS configurations are correctly enforced. For teams using the GitHub Action, you can add API security checks to your CI/CD pipeline to fail builds if weak TLS settings are detected before deployment. The Web Dashboard can help track mTLS-related findings over time, and the MCP Server allows you to scan APIs directly from your AI coding assistant within your development environment.