Dns Rebinding in Feathersjs with Cockroachdb

DNS Rebinding occurs when an attacker forces a victim’s browser to resolve a domain to an internal IP address that is otherwise not reachable from the public internet. In a Feathersjs application that uses Cockroachdb as its backend, this becomes relevant when the server trusts internal network origins or exposes administrative interfaces over local endpoints. Feathersjs services often interact with databases via custom transports or hooks; if the service resolves or connects to a Cockroachdb instance using hostnames that can be manipulated, an attacker may pivot from a public-facing endpoint to internal database listeners.

Consider a Feathersjs server configured with a Cockroachdb connection string that includes a hostname resolvable both publicly and internally (e.g., a service name that resolves to a public IP during initial DNS lookup but later resolves to a private IP via a malicious DNS response). If Feathersjs does not enforce strict host validation or network segmentation, the runtime connection may switch to an internal Cockroachdb node that accepts connections without additional authentication checks from the application layer. This exposes the database to unauthorized queries or configuration reads, especially when the Feathersjs service uses elevated database credentials for simplicity.

The vulnerability is compounded when Feathersjs routes or hooks do not validate the origin of requests and when Cockroachdb is accessible on non-standard ports or without TLS from the application server. For example, a Feathersjs hook that dynamically selects a Cockroachdb node based on request metadata could be tricked into connecting to a malicious listener that proxies traffic to an internal node. Because the scan testing methodology of middleBrick evaluates unauthenticated attack surfaces across multiple concurrent checks, such misconfigurations can be detected without credentials, highlighting exposure paths specific to the Feathersjs + Cockroachdb stack.

Real-world attack patterns include embedding a rogue hostname in a compromised web page visited by an authenticated user, or leveraging a vulnerable subdomain to serve DNS responses that point to internal IPs. OWASP API Top 10’s Broken Object Level Authorization and Security Misconfiguration categories intersect here, as does the broader risk of SSRF when internal endpoints are reachable. middleBrick’s checks for SSRF, Input Validation, and Property Authorization are designed to surface these classes of risk when scanning a Feathersjs API that interfaces with Cockroachdb.

In practice, the interaction is not inherently insecure—proper network controls, strict hostname verification, and firewall rules mitigate the danger—but the combination of dynamic service discovery in Feathersjs and Cockroachdb’s multi-node topology increases the complexity of ensuring that only intended endpoints are reachable. MiddleBrick’s findings in such scenarios typically recommend removing internal hostnames from runtime resolution paths and enforcing strict source validation at the Feathersjs service layer.

Remediation centers on ensuring that Feathersjs never resolves hostnames at runtime in a way that can be influenced by an attacker, and that connections to Cockroachdb are performed only to explicitly whitelisted endpoints with strong transport security.

First, hardcode or securely inject the Cockroachdb host and port at deployment time, avoiding any user-supplied values in connection strings. Use environment variables that are set by your infrastructure, not derived from requests or configuration files that an attacker can modify through the API surface.

// Safe connection configuration for Cockroachdb in Feathersjs
const { Sequelize } = require('sequelize');
const db = new Sequelize({
  dialect: 'postgres',
  host: process.env.COCKROACH_HOST || 'localhost',
  port: parseInt(process.env.COCKROACH_PORT, 10) || 26257,
  database: process.env.COCKROACH_DB || 'mydb',
  username: process.env.COCKROACH_USER || 'admin',
  password: process.env.COCKROACH_PASSWORD,
  ssl: {
    require: true,
    rejectUnauthorized: true
  },
  define: {
    timestamps: true
  }
});

Second, enforce strict server-side validation in Feathersjs hooks to ensure that no request parameters or headers influence host selection. Avoid dynamic lookup logic that queries service discovery or configuration endpoints based on request content.

// Feathersjs hook to validate service access boundaries
const validateDbTarget = context =>
  Promise.resolve(context);

// Use as a before hook in your Feathersjs service
app.service('reports').hooks({
  before: {
    all: [validateDbTarget]
  }
});

Third, implement network-level controls by binding Cockroachdb listeners only to specific interfaces and using firewall rules to restrict access to known Feathersjs server IPs. If you must allow broader access, enforce mTLS between Feathersjs and Cockroachdb so that the database verifies the server certificate on each connection. Below is a Cockroachdb connection snippet that enforces TLS verification, which complements Feathersjs-side discipline.

// Cockroachdb with enforced TLS in a Node.js Feathersjs app
const fs = require('fs');
const { Sequelize } = require('sequelize');

const sslCert = fs.readFileSync('/path/to/client.crt');
const sslKey = fs.readFileSync('/path/to/client.key');
const sslCa = fs.readFileSync('/path/to/ca.crt');

const db = new Sequelize({
  dialect: 'postgres',
  host: process.env.COCKROACH_HOST,
  port: process.env.COCKROACH_PORT,
  database: process.env.COCKROACH_DB,
  username: process.env.COCKROACH_USER,
  password: process.env.COCKROACH_PASSWORD,
  protocol: 'postgres',
  dialectModule: require('pg'),
  ssl: {
    cert: sslCert,
    key: sslKey,
    ca: sslCa,
    rejectUnauthorized: true
  },
  logging: false
});

Finally, rotate credentials and monitor connection patterns. Use middleBrick’s scans to verify that your Feathersjs endpoints do not expose internal Cockroachdb interfaces and that input validation blocks any attempt to influence resolution paths. The platform’s findings related to Input Validation, Property Authorization, and SSRF can guide targeted hardening of your service configuration.