GHSA-qm95-pgcg-qqfq Insufficient validation when decoding a Socket.IO packet

• npm socket.io-parser: >= 4.0.0, < 4.0.5 → fixed in 4.0.5 • npm socket.io-parser: >= 4.1.0, < 4.2.1 → fixed in 4.2.1 • npm socket.io-parser: < 3.3.3 → fixed in 3.3.3 • npm socket.io-parser: >= 3.4.0, < 3.4.2 → fixed in 3.4.2

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: ```js 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: ```js 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: ```js 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: • a number that is out of bounds Sample packet: `451-["hello",{"_placeholder":true,"num":10}]` ```js io.on("connection", (socket) => { socket.on("hello", (val) => { // val is `undefined` }); }); ``` • a value that is not a number, like `undefined` Sample packet: `451-["hello",{"_placeholder":true,"num":undefined}]` ```js io.on("connection", (socket) => { socket.on("hello", (val) => { // val is `undefined` }); }); ``` • a string that is part of the prototype of `Array`, like "push" Sample packet: `451-["hello",{"_placeholder":true,"num":"push"}]` ```js io.on("connection", (socket) => { socket.on("hello", (val) => { // val is a reference to the "push" function }); }); ``` • a string that is part of the prototype of `Object`, like "hasOwnProperty" Sample packet: `451-["hello",{"_placeholder":true,"num":"hasOwnProperty"}]` ```js io.on("connection", (socket) => { socket.on("hello", (val) => { // val is a reference to the "hasOwnProperty" function }); }); ``` This should be fixed by: • https://github.com/socketio/socket.io-parser/commit/b5d0cb7dc56a0601a09b056beaeeb0e43b160050, included in `[email protected]` • https://github.com/socketio/socket.io-parser/commit/b559f050ee02bd90bd853b9823f8de7fa94a80d4, included in `[email protected]` • https://github.com/socketio/socket.io-parser/commit/04d23cecafe1b859fb03e0cbf6ba3b74dff56d14, included in `[email protected]` • https://github.com/socketio/socket.io-parser/commit/fb21e422fc193b34347395a33e0f625bebc09983, included in `[email protected]` Dependency analysis for the `socket.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: | Dependency analysis for the `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: |