Insufficient validation when decoding a Socket.IO packet

Impact

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

Patches

A fix has been released today (2023/05/22):

• https://github.com/socketio/socket.io-parser/commit/3b78117bf6ba7e99d7a5cfc1ba54d0477554a7f3, included in socket.io-parser@4.2.3
• https://github.com/socketio/socket.io-parser/commit/2dc3c92622dad113b8676be06f23b1ed46b02ced, included in socket.io-parser@3.4.3

Another fix has been released for the 3.3.x branch:

• https://github.com/socketio/socket.io-parser/commit/ee006607495eca4ec7262ad080dd3a91439a5ba4, included in `socket.io-parser@3.3.4

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

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 a discussion here

Thanks to @rafax00 for the responsible disclosure.