Uncaught exception in engine.io

Impact

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`.

Patches

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 |

Workarounds

There is no known workaround except upgrading to a safe version.

For more information

If you have any questions or comments about this advisory:

• Open an issue in `engine.io`

Thanks to Jonathan Neve for the responsible disclosure.