CVE-2025-23083: Manipulating Worker Threads via Diagnostics_Channel Utility in Node.js Versions 20, 22, and 23

The discovery of a new vulnerability, dubbed CVE-2025-23083, in Node.js has raised concerns over the security risks it poses to users of specific versions. This vulnerability allows an attacker to manipulate worker threads in Node.js by taking advantage of the diagnostics_channel utility. Such a breach could result in the hijacking of internal workers, potentially exposing sensitive information and allowing for malicious usage. This post aims to provide a comprehensive overview of the exploit, as well as original references and code snippets to help users identify the vulnerability and take appropriate action.

Exploit Details

The diagnostics_channel utility in Node.js works as a medium to hook into events related to worker threads. CVE-2025-23083 exposes a loophole in the utility that grants unauthorized access to not just worker threads but also internal workers. An attacker could then acquire an instance of these internal workers, hijack their constructors, and repurpose them for malicious activities.

Affected Node.js Versions

This vulnerability is specific to Node.js versions 20, 22, and 23, particularly for users employing the Permission Model (--permission) functionality.

Code Snippet Example

The following code snippet illustrates how an attacker might leverage the diagnostics_channel to gain access to internal workers.

const dc = require('diagnostics_channel');
const {
  internalBinding
} = require('node:worker_threads');

dc.channel('node.worker_thread_creation').subscribe(({ worker }) => {
  const InternalWorker = internalBinding('worker').Worker;
  const hijackedConstructor = InternalWorker.prototype.constructor;
  
  // Malicious codes can be placed here to manipulate the internal worker instance...
  console.log('[+] Internal Worker instance hijacked:', worker);
});

For more information on the diagnostics_channel utility, consult the official Node.js documentation

- Diagnostics Channel (Node.js v16.13.1 Documentation)

The Node.js Security Working Group provides essential resources regarding security policies and vulnerability disclosures:

- Node.js Security Working Group

Mitigation and Solutions

Users are urged to take immediate action and upgrade to a secure version of Node.js that is not vulnerable to this issue. The Node.js project team continuously works on addressing vulnerabilities and providing security patches.

Conclusion

The CVE-2025-23083 vulnerability poses a significant risk to Permission Model users on specific Node.js versions. By exploiting this vulnerability, an attacker could compromise worker threads and internal workers for malicious purposes. It is crucial for users to be aware of the issue and take timely action to mitigate the risk by upgrading their Node.js installations. Stay informed on the latest security updates and best practices to safeguard your applications against evolving threats.

Timeline

Published on: 01/22/2025 02:15:33 UTC
Last modified on: 02/06/2025 15:15:17 UTC