CVE-2023-49293 PoC — Cross-site Scripting in `server.transformIndexHtml` via URL payload in vite

Title:Cross-site Scripting in `server.transformIndexHtml` via URL payload in vite (CVE-2023-49293)
Description:Vite is a website frontend framework. When Vite's HTML transformation is invoked manually via `server.transformIndexHtml`, the original request URL is passed in unmodified, and the `html` being transformed contains inline module scripts (`<script type="module">...</script>`), it is possible to inject arbitrary HTML into the transformed output by supplying a malicious URL query string to `server.transformIndexHtml`. Only apps using `appType: 'custom'` and using the default Vite HTML middleware are affected. The HTML entry must also contain an inline script. The attack requires a user to click on a malicious URL while running the dev server. Restricted files aren't exposed to the attacker. This issue has been addressed in vite@5.0.5, vite@4.5.1, and vite@4.4.12. There are no known workarounds for this vulnerability.

Vite's dev server, when used with `appType: 'custom'` and manually invoking `server.transformIndexHtml` using the unmodified request URL, is vulnerable to XSS via a crafted URL payload. If the HTML being served includes an inline module script (`<script type="module">...</script>`), an attacker can inject a script via the URL, potentially leading to XSS in the browser. The vulnerability only affects certain custom SSR/dev configurations, not plain `vite dev`.

 id: CVE-2023-49293

info:
  name: Vite dev server - Cross-Site Scripting
  author: ritikchaddha
  se

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