GHSA-rcvg-rgf7-pppv

### Summary Nuxt Devtools is missing authentication on the `getTextAssetContent` RPC function which is vulnerable to path traversal. Combined with a lack of Origin checks on the WebSocket handler, an attacker is able to interact with a locally running devtools instance and exfiltrate data abusing this vulnerability. In certain configurations an attacker could leak the devtools authentication token and then abuse other RPC functions to achieve RCE. ### Details The `getTextAssetContent` function does not check for path traversals [(source)](https://github.com/nuxt/devtools/blob/c4f2b68281203fc3f61ffc97d9c6623fbfde46bb/packages/devtools/src/server-rpc/assets.ts#L88C48-L88C48), this could allow an attacker to read arbitrary files over the RPC WebSocket. The WebSocket server does not check the origin of the request [(source)](https://github.com/nuxt/devtools/blob/c4f2b68281203fc3f61ffc97d9c6623fbfde46bb/packages/devtools/src/server-rpc/index.ts#L109) leading to [CSWSH](https://portswigger.net/web-security/websockets/cross-site-websocket-hijacking). This may be intentional to allow certain configurations to work correctly. Nuxt Devtools authentication tokens are placed within the home directory of the current user [(source)](https://github.com/nuxt/devtools/blob/c4f2b68281203fc3f61ffc97d9c6623fbfde46bb/packages/devtools/src/dev-auth.ts#L14). In the scenario that: + The user has a Nuxt3 Project running + Devtools is enabled and running + The project is placed within the users home directory. + The user visits a malicious webpage + User has authenticated with devtools at least once The malicious webpage can connect to the Devtools WebSocket, perform a directory traversal brute force to find the authentication token, then use the *authenticated* [`writeStaticAssets` function](https://github.com/nuxt/devtools/blob/c4f2b68281203fc3f61ffc97d9c6623fbfde46bb/packages/devtools/src/server-rpc/assets.ts#L96C11-L96C28) to create a new Component, Nitro Handler or `app.vue` file which will run automatically as the file is changed. ### PoC POC will exploit the Devtools server on localhost:3000 (you may need to manually restart the server as the restart hook does not always work). POC: https://devtools-exploit.pages.dev 1. Create a new project with nuxt.new. 2. Place the project inside your home directory. 3. Run `pnpm run dev`. 4. Open the POC page. The POC will: + Identify devtools version. + Leak your devtools token. + Create a new server handler with an insecure eval. ### Impact + All new Nuxt projects by default (devtools is enabled) are vulnerable to arbitrary file read. + Certain Nuxt configurations are vulnerable to Remote Code Execution