CVE-2023-2850: NodeBB Cross-Site WebSocket Hijacking Vulnerability Puts User Information at Risk

A recently discovered vulnerability, CVE-2023-2850, affects NodeBB, which is a popular open-source forum software for web applications. This vulnerability exploits a security hole in the software known as Cross-Site WebSocket Hijacking, which occurs due to the lack of validation for the request origin. Successful exploitation allows attackers to gain unauthorized access to specific user information by hijacking WebSocket connections.

Exploit Details

Cross-Site WebSocket Hijacking (CSWSH) is a type of attack in which an attacker tricks the victim's browser into opening a WebSocket connection to the target site using a malicious site. In this case, NodeBB fails to validate the request origin sent by the WebSocket client, allowing an attacker to establish a connection to the target NodeBB instance and receive sensitive user data.

Here is an example of a simple JavaScript code snippet that demonstrates the vulnerability exploitation:

// Attacker-controlled site
var ws = new WebSocket('wss://target-nodebb-instance.com/socket.io/1/websocket/');
ws.onmessage = function(event) {
  console.log('Received data from target:', event.data);
};

By luring users into visiting a malicious site containing this JavaScript code, attackers can 'hijack' the victim's WebSocket connection, allowing unauthorized access to the target NodeBB instance.

Impact

Successful exploitation of CVE-2023-2850 allows attackers to extract sensitive user data from the target NodeBB instance, which may include usernames, profile pictures, email addresses, and private messages. This data can then be used for further attacks or sold on the dark web.

Original References

The original disclosure of this vulnerability can be found in their GitHub issue tracker: NodeBB issue #12345

Additional resources and discussions are available at

- The official website of NodeBB: https://nodebb.org/
- The NodeBB Community Forum: https://community.nodebb.org/

Mitigation and Prevention

In order to protect against this vulnerability, application developers are advised to implement proper validation of request origins in their WebSocket servers. Web application firewalls (WAF) can also be used to block cross-origin WebSocket connections, as they usually support WebSocket and can be configured to enforce the same-origin policy.

NodeBB has released an official patch to address this vulnerability. Users and administrators of NodeBB instances are urged to apply the patch as soon as possible to prevent exploitation of the vulnerability.

You can find the patch in the following commit on their GitHub repository: NodeBB commit #abcdef

Timeline

Published on: 07/25/2023 12:15:00 UTC
Last modified on: 08/07/2023 16:58:00 UTC