Socket.IO version 4.5.0 represents a minor update over the previous stable version, 4.4.1, focusing primarily on dependency upgrades and internal improvements rather than groundbreaking new features. For developers, this means a smoother, potentially more performant experience without the need for significant code rewrites.
Key changes reside within the dependency tree. The engine.io package, responsible for the low-level transport mechanisms, sees an update from version 6.1.0 to 6.2.0, possibly introducing performance enhancements related to websocket connections and handling of different network conditions. The socket.io-adapter has been bumped up from 2.3.3 to 2.4.0, potentially impacting how Socket.IO scales across multiple server instances, a relevant factor for larger, high-traffic applications. Moreover the socket.io-client has been bumped to version 4.5.0, which means developers that use them together, now have both matched versions.
Beyond these explicit dependency bumps, the package size sees a slight increase, with the unpacked size growing from 984KB to 1033KB. This potentially indicates increased code complexity or the inclusion of previously optional features. While the core API remains largely consistent, it's advisable to review the Socket.IO changelog for any subtle modifications impacting existing implementations, particularly concerning the upgraded dependencies. Developers should also note the later release date of v4.5.0 in April 2022 compared to v4.4.1 in January 2022, suggesting fixes for bugs or security vulnerabilities discovered in the earlier version. For new projects, v4.5.0 is the recommended starting point.
All the vulnerabilities related to the version 4.5.0 of the package
socket.io has an unhandled 'error' event
A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process.
node:events:502
throw err; // Unhandled 'error' event
^
Error [ERR_UNHANDLED_ERROR]: Unhandled error. (undefined)
at new NodeError (node:internal/errors:405:5)
at Socket.emit (node:events:500:17)
at /myapp/node_modules/socket.io/lib/socket.js:531:14
at process.processTicksAndRejections (node:internal/process/task_queues:77:11) {
code: 'ERR_UNHANDLED_ERROR',
context: undefined
}
| Version range | Needs minor update? |
|------------------|------------------------------------------------|
| 4.6.2...latest | Nothing to do |
| 3.0.0...4.6.1 | Please upgrade to socket.io@4.6.2 (at least) |
| 2.3.0...2.5.0 | Please upgrade to socket.io@2.5.1 |
This issue is fixed by https://github.com/socketio/socket.io/commit/15af22fc22bc6030fcead322c106f07640336115, included in socket.io@4.6.2 (released in May 2023).
The fix was backported in the 2.x branch today: https://github.com/socketio/socket.io/commit/d30630ba10562bf987f4d2b42440fc41a828119c
As a workaround for the affected versions of the socket.io package, you can attach a listener for the "error" event:
io.on("connection", (socket) => {
socket.on("error", () => {
// ...
});
});
If you have any questions or comments about this advisory:
Thanks a lot to Paul Taylor for the responsible disclosure.
engine.io Uncaught Exception vulnerability
A specially crafted HTTP request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process.
TypeError: Cannot read properties of undefined (reading 'handlesUpgrades')
at Server.onWebSocket (build/server.js:515:67)
This impacts all the users of the engine.io package, including those who uses depending packages like socket.io.
A fix has been released today (2023/05/02): 6.4.2
This bug was introduced in version 5.1.0 and included in version 4.1.0 of the socket.io parent package. Older versions are not impacted.
For socket.io users:
| Version range | engine.io version | Needs minor update? |
|-----------------------------|---------------------|--------------------------------------------------------------------------------------------------------|
| socket.io@4.6.x | ~6.4.0 | npm audit fix should be sufficient |
| socket.io@4.5.x | ~6.2.0 | Please upgrade to socket.io@4.6.x |
| socket.io@4.4.x | ~6.1.0 | Please upgrade to socket.io@4.6.x |
| socket.io@4.3.x | ~6.0.0 | Please upgrade to socket.io@4.6.x |
| socket.io@4.2.x | ~5.2.0 | Please upgrade to socket.io@4.6.x |
| socket.io@4.1.x | ~5.1.1 | Please upgrade to socket.io@4.6.x |
| socket.io@4.0.x | ~5.0.0 | Not impacted |
| socket.io@3.1.x | ~4.1.0 | Not impacted |
| socket.io@3.0.x | ~4.0.0 | Not impacted |
| socket.io@2.5.0 | ~3.6.0 | Not impacted |
| socket.io@2.4.x and below | ~3.5.0 | Not impacted |
There is no known workaround except upgrading to a safe version.
If you have any questions or comments about this advisory:
engine.ioThanks to Thomas Rinsma from Codean for the responsible disclosure.
ws affected by a DoS when handling a request with many HTTP headers
A request with a number of headers exceeding theserver.maxHeadersCount threshold could be used to crash a ws server.
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();
});
The vulnerability was fixed in ws@8.17.1 (https://github.com/websockets/ws/commit/e55e5106f10fcbaac37cfa89759e4cc0d073a52c) and backported to ws@7.5.10 (https://github.com/websockets/ws/commit/22c28763234aa75a7e1b76f5c01c181260d7917f), ws@6.2.3 (https://github.com/websockets/ws/commit/eeb76d313e2a00dd5247ca3597bba7877d064a63), and ws@5.2.4 (https://github.com/websockets/ws/commit/4abd8f6de4b0b65ef80b3ff081989479ed93377e)
In vulnerable versions of ws, the issue can be mitigated in the following ways:
--max-http-header-size=size and/or the maxHeaderSize options so that no more headers than the server.maxHeadersCount limit can be sent.server.maxHeadersCount to 0 so that no limit is applied.The vulnerability was reported by Ryan LaPointe in https://github.com/websockets/ws/issues/2230.
cookie accepts cookie name, path, and domain with out of bounds characters
The cookie name could be used to set other fields of the cookie, resulting in an unexpected cookie value. For example, serialize("userName=<script>alert('XSS3')</script>; Max-Age=2592000; a", value) would result in "userName=<script>alert('XSS3')</script>; Max-Age=2592000; a=test", setting userName cookie to <script> and ignoring value.
A similar escape can be used for path and domain, which could be abused to alter other fields of the cookie.
Upgrade to 0.7.0, which updates the validation for name, path, and domain.
Avoid passing untrusted or arbitrary values for these fields, ensure they are set by the application instead of user input.
Insufficient validation when decoding a Socket.IO packet
A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process.
TypeError: Cannot convert object to primitive value
at Socket.emit (node:events:507:25)
at .../node_modules/socket.io/lib/socket.js:531:14
A fix has been released today (2023/05/22):
socket.io-parser@4.2.3socket.io-parser@3.4.3Another fix has been released for the 3.3.x branch:
| socket.io version | socket.io-parser version | Needs minor update? |
|---------------------|---------------------------------------------------------------------------------------------------------|--------------------------------------|
| 4.5.2...latest | ~4.2.0 (ref) | npm audit fix should be sufficient |
| 4.1.3...4.5.1 | ~4.1.1 (ref) | Please upgrade to socket.io@4.6.x |
| 3.0.5...4.1.2 | ~4.0.3 (ref) | Please upgrade to socket.io@4.6.x |
| 3.0.0...3.0.4 | ~4.0.1 (ref) | Please upgrade to socket.io@4.6.x |
| 2.3.0...2.5.0 | ~3.4.0 (ref) | npm audit fix should be sufficient |
There is no known workaround except upgrading to a safe version.
If you have any questions or comments about this advisory:
Thanks to @rafax00 for the responsible disclosure.