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 [email protected]
• https://github.com/socketio/socket.io-parser/commit/2dc3c92622dad113b8676be06f23b1ed46b02ced, included in [email protected]

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

• https://github.com/socketio/socket.io-parser/commit/ee006607495eca4ec7262ad080dd3a91439a5ba4, included in `[email protected]

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.