Socket.IO underwent a significant evolution between versions 0.9.19 and 1.0.0, introducing architectural changes that impact how developers build real-time applications. Version 0.9.19 relied on dependencies like redis (also listed as an optional dependency), base64id, and policyfile, embedding functionality directly within the core package. In contrast, version 1.0.0 embraces a more modular approach, deferring core functionalities to a set of isolated well-defined packages.
This shift is evident in the dependencies. The direct dependency on redis disappears, reflecting a move towards a more generalized model for data persistence; instead version 1.0.0 introduces socket.io-adapter, suggesting a pluggable architecture that allows for different persistance/clustering implementation via custom adapters. The new version relies on engine.io for its core transport mechanism, socket.io-parser for message parsing, and has-binary-data to manage binary data efficiently. This decoupling clarifies responsibilities and strengthens the overall architecture of the library. Importantly, socket.io-client remains a dependency in both versions, underlining its role as the client-side component for seamless communication.
Developers migrating to version 1.0.0 will find a more structured and extensible framework that provides increased flexibility and modularity. The move away from direct Redis dependency could either be a breaking change by removing built-in support or a welcomed change that provides a more modular way to configure persistence options. The new dependencies indicate better handling of real-time functionalities that socket.io offers. Version 1.0.0 introduces significant performance and scalability improvements.
All the vulnerabilities related to the version 1.0.0 of the package
CORS misconfiguration in socket.io
The package socket.io before 2.4.0 are vulnerable to Insecure Defaults due to CORS Misconfiguration. All domains are whitelisted by default.
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.
debug Inefficient Regular Expression Complexity vulnerability
A vulnerability classified as problematic has been found in debug-js debug up to 3.0.x. This affects the function useColors of the file src/node.js. The manipulation of the argument str leads to inefficient regular expression complexity. Upgrading to version 3.1.0 is able to address this issue. The name of the patch is c38a0166c266a679c8de012d4eaccec3f944e685. It is recommended to upgrade the affected component. The identifier VDB-217665 was assigned to this vulnerability. The patch has been backported to the 2.6.x branch in version 2.6.9.
Regular Expression Denial of Service in debug
Affected versions of debug are vulnerable to regular expression denial of service when untrusted user input is passed into the o formatter.
As it takes 50,000 characters to block the event loop for 2 seconds, this issue is a low severity issue.
This was later re-introduced in version v3.2.0, and then repatched in versions 3.2.7 and 4.3.1.
Version 2.x.x: Update to version 2.6.9 or later. Version 3.1.x: Update to version 3.1.0 or later. Version 3.2.x: Update to version 3.2.7 or later. Version 4.x.x: Update to version 4.3.1 or later.
Resource exhaustion in engine.io
Engine.IO before 4.0.0 and 3.6.0 allows attackers to cause a denial of service (resource consumption) via a POST request to the long polling transport.
Uncaught exception in engine.io
A specially crafted HTTP request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process.
events.js:292
throw er; // Unhandled 'error' event
^
Error: read ECONNRESET
at TCP.onStreamRead (internal/stream_base_commons.js:209:20)
Emitted 'error' event on Socket instance at:
at emitErrorNT (internal/streams/destroy.js:106:8)
at emitErrorCloseNT (internal/streams/destroy.js:74:3)
at processTicksAndRejections (internal/process/task_queues.js:80:21) {
errno: -104,
code: 'ECONNRESET',
syscall: 'read'
}
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 (2022/11/20):
| Version range | Fixed version |
|-------------------|---------------|
| engine.io@3.x.y | 3.6.1 |
| engine.io@6.x.y | 6.2.1 |
For socket.io users:
| Version range | engine.io version | Needs minor update? |
|-----------------------------|---------------------|--------------------------------------------------------------------------------------------------------|
| socket.io@4.5.x | ~6.2.0 | npm audit fix should be sufficient |
| socket.io@4.4.x | ~6.1.0 | Please upgrade to socket.io@4.5.x |
| socket.io@4.3.x | ~6.0.0 | Please upgrade to socket.io@4.5.x |
| socket.io@4.2.x | ~5.2.0 | Please upgrade to socket.io@4.5.x |
| socket.io@4.1.x | ~5.1.1 | Please upgrade to socket.io@4.5.x |
| socket.io@4.0.x | ~5.0.0 | Please upgrade to socket.io@4.5.x |
| socket.io@3.1.x | ~4.1.0 | Please upgrade to socket.io@4.5.x (see here) |
| socket.io@3.0.x | ~4.0.0 | Please upgrade to socket.io@4.5.x (see here) |
| socket.io@2.5.0 | ~3.6.0 | npm audit fix should be sufficient |
| socket.io@2.4.x and below | ~3.5.0 | Please upgrade to socket.io@2.5.0 |
There is no known workaround except upgrading to a safe version.
If you have any questions or comments about this advisory:
engine.ioThanks to Jonathan Neve for the responsible disclosure.
Remote Memory Disclosure in ws
Versions of ws prior to 1.0.1 are affected by a remote memory disclosure vulnerability.
In certain rare circumstances, applications which allow users to control the arguments of a client.ping() call will cause ws to send the contents of an allocated but non-zero-filled buffer to the server. This may disclose sensitive information that still exists in memory after previous use of the memory for other tasks.
var ws = require('ws')
var server = new ws.Server({ port: 9000 })
var client = new ws('ws://localhost:9000')
client.on('open', function () {
console.log('open')
client.ping(50) // this sends a non-zeroed buffer of 50 bytes
client.on('pong', function (data) {
console.log('got pong')
console.log(data) // Data from the client.
})
})
Update to version 1.0.1 or greater.
DoS due to excessively large websocket message in ws
Affected versions of ws do not appropriately limit the size of incoming websocket payloads, which may result in a denial of service condition when the node process crashes after receiving a large payload.
Update to version 1.1.1 or later.
Alternatively, set the maxpayload option for the ws server to a value smaller than 256MB.
Denial of Service in ws
Affected versions of ws can crash when a specially crafted Sec-WebSocket-Extensions header containing Object.prototype property names as extension or parameter names is sent.
const WebSocket = require('ws');
const net = require('net');
const wss = new WebSocket.Server({ port: 3000 }, function () {
const payload = 'constructor'; // or ',;constructor'
const request = [
'GET / HTTP/1.1',
'Connection: Upgrade',
'Sec-WebSocket-Key: test',
'Sec-WebSocket-Version: 8',
`Sec-WebSocket-Extensions: ${payload}`,
'Upgrade: websocket',
'\r\n'
].join('\r\n');
const socket = net.connect(3000, function () {
socket.resume();
socket.write(request);
});
});
Update to version 3.3.1 or later.
Resource exhaustion in socket.io-parser
The socket.io-parser npm package before versions 3.3.2 and 3.4.1 allows attackers to cause a denial of service (memory consumption) via a large packet because a concatenation approach is used.
Insufficient validation when decoding a Socket.IO packet
Due to improper type validation in the socket.io-parser library (which is used by the socket.io and socket.io-client packages to encode and decode Socket.IO packets), it is possible to overwrite the _placeholder object which allows an attacker to place references to functions at arbitrary places in the resulting query object.
Example:
const decoder = new Decoder();
decoder.on("decoded", (packet) => {
console.log(packet.data); // prints [ 'hello', [Function: splice] ]
})
decoder.add('51-["hello",{"_placeholder":true,"num":"splice"}]');
decoder.add(Buffer.from("world"));
This bubbles up in the socket.io package:
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// here, "val" could be a function instead of a buffer
});
});
:warning: IMPORTANT NOTE :warning:
You need to make sure that the payload that you received from the client is actually a Buffer object:
io.on("connection", (socket) => {
socket.on("hello", (val) => {
if (!Buffer.isBuffer(val)) {
socket.disconnect();
return;
}
// ...
});
});
If that's already the case, then you are not impacted by this issue, and there is no way an attacker could make your server crash (or escalate privileges, ...).
Example of values that could be sent by a malicious user:
Sample packet: 451-["hello",{"_placeholder":true,"num":10}]
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// val is `undefined`
});
});
undefinedSample packet: 451-["hello",{"_placeholder":true,"num":undefined}]
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// val is `undefined`
});
});
Array, like "push"Sample packet: 451-["hello",{"_placeholder":true,"num":"push"}]
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// val is a reference to the "push" function
});
});
Object, like "hasOwnProperty"Sample packet: 451-["hello",{"_placeholder":true,"num":"hasOwnProperty"}]
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// val is a reference to the "hasOwnProperty" function
});
});
This should be fixed by:
socket.io-parser@4.2.1socket.io-parser@4.0.5socket.io-parser@3.4.2socket.io-parser@3.3.3socket.io package| socket.io version | socket.io-parser version | Covered? |
|---------------------|---------------------------------------------------------------------------------------------------------|------------------------|
| 4.5.2...latest | ~4.2.0 (ref) | Yes :heavy_check_mark: |
| 4.1.3...4.5.1 | ~4.0.4 (ref) | Yes :heavy_check_mark: |
| 3.0.5...4.1.2 | ~4.0.3 (ref) | Yes :heavy_check_mark: |
| 3.0.0...3.0.4 | ~4.0.1 (ref) | Yes :heavy_check_mark: |
| 2.3.0...2.5.0 | ~3.4.0 (ref) | Yes :heavy_check_mark: |
socket.io-client package| socket.io-client version | socket.io-parser version | Covered? |
|----------------------------|----------------------------------------------------------------------------------------------------------------|------------------------------------|
| 4.5.0...latest | ~4.2.0 (ref) | Yes :heavy_check_mark: |
| 4.3.0...4.4.1 | ~4.1.1 (ref) | No, but the impact is very limited |
| 3.1.0...4.2.0 | ~4.0.4 (ref) | Yes :heavy_check_mark: |
| 3.0.5 | ~4.0.3 (ref) | Yes :heavy_check_mark: |
| 3.0.0...3.0.4 | ~4.0.1 (ref) | Yes :heavy_check_mark: |
| 2.2.0...2.5.0 | ~3.3.0 (ref) | Yes :heavy_check_mark: |
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.