Engine.IO versions 3.4.1 and 3.4.2 are incremental updates to a core component behind Socket.IO, providing the foundation for bidirectional real-time communication between clients and servers. Both share the same fundamental purpose: enabling persistent, low-latency connections. Developers using Engine.IO benefit from its robust implementation of various transport mechanisms, including WebSocket and HTTP long-polling, ensuring broad compatibility across different environments.
Examining the dependencies, both versions rely on the same core modules, such as "ws" for WebSocket support, "debug" for logging, "cookie" for handling cookies, "accepts" for content negotiation, "base64id" for generating unique identifiers, and "engine.io-parser" for message encoding/decoding. The development dependencies also appear identical.
The key differences lie in the engine.io-client version and potentially in bug fixes or performance improvements. Version 3.4.1 uses the client library of the same version while version 3.4.2 uses the corresponding 3.4.2 client library. The newer version has a slightly bigger unpacked size, which could indicate new features or improvements but is usually only bug fixes, which don't change the interface but improve stability. Upgrading from 3.4.1 to 3.4.2 should generally be a straightforward process, provided developers ensure compatibility with any subtle internal changes or bug fixes implemented in the newer release. Most developers should be able to seamlessly leverage the enhanced stability if any. The release date informs of the freshness of the release and the continuous support from the development team.
All the vulnerabilities related to the version 3.4.2 of the package
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.
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.
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.