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.
Impact
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.
Patches
Fixed in vite@5.0.5, vite@4.5.1, vite@4.4.12
Details
Suppose index.html contains an inline module script:
<script type="module">
// Inline script
</script>
This script is transformed into a proxy script like
so the url passed to server.transformIndexHtml is /index.html.
However, if appType: 'custom', HTML is served manually, and if server.transformIndexHtml is called with the unmodified request URL (as the SSR docs suggest), then the path of the transformed html-proxy script varies with the request URL. For example, a request with path / produces
However, since this vulnerability affects server.transformIndexHtml, the scope of impact may be higher to also include other ad-hoc calls to server.transformIndexHtml from outside of Vite's own codebase.
My best guess at bisecting which versions are vulnerable involves the following test script
import fs from 'node:fs/promises';
import * as vite from 'vite';
const html = `
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
</head>
<body>
<script type="module">
// Inline script
</script>
</body>
</html>
`;
const server = await vite.createServer({ appType: 'custom' });
const transformed = await server.transformIndexHtml('/?%22%3E%3C/script%3E%3Cscript%3Ealert(%27boom%27)%3C/script%3E', html);
console.log(transformed);
await server.close();
and using it I was able to narrow down to #13581. If this is correct, then vulnerable Vite versions are 4.4.0-beta.2 and higher (which includes 4.4.0).
Release Notes
vitejs/vite (vite)
### [`v4.5.1`](https://togithub.com/vitejs/vite/releases/tag/v4.5.1)
[Compare Source](https://togithub.com/vitejs/vite/compare/v4.5.0...v4.5.1)
Please refer to [CHANGELOG.md](https://togithub.com/vitejs/vite/blob/v4.5.1/packages/vite/CHANGELOG.md) for details.
Configuration
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This PR contains the following updates:
4.5.0
->4.5.1
GitHub Vulnerability Alerts
CVE-2023-49293
Summary
When Vite's HTML transformation is invoked manually via
server.transformIndexHtml
, the original request URL is passed in unmodified, and thehtml
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 toserver.transformIndexHtml
.Impact
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.Patches
Fixed in vite@5.0.5, vite@4.5.1, vite@4.4.12
Details
Suppose
index.html
contains an inline module script:This script is transformed into a proxy script like
due to Vite's HTML plugin:
https://github.com/vitejs/vite/blob/7fd7c6cebfcad34ae7021ebee28f97b1f28ef3f3/packages/vite/src/node/plugins/html.ts#L429-L465
When
appType: 'spa' | 'mpa'
, Vite serves HTML itself, andhtmlFallbackMiddleware
rewritesreq.url
to the canonical path ofindex.html
,https://github.com/vitejs/vite/blob/73ef074b80fa7252e0c46a37a2c94ba8cba46504/packages/vite/src/node/server/middlewares/htmlFallback.ts#L44-L47
so the
url
passed toserver.transformIndexHtml
is/index.html
.However, if
appType: 'custom'
, HTML is served manually, and ifserver.transformIndexHtml
is called with the unmodified request URL (as the SSR docs suggest), then the path of the transformedhtml-proxy
script varies with the request URL. For example, a request with path/
producesIt is possible to abuse this behavior by crafting a request URL to contain a malicious payload like
so a request to http://localhost:5173/?%22%3E%3C/script%3E%3Cscript%3Ealert(%27boom%27)%3C/script%3E produces HTML output like
which demonstrates XSS.
PoC
vite dev
middleware withappType: 'custom'
?%22%3E%3C/script%3E%3Cscript%3Ealert(%27boom%27)%3C/script%3E
and navigatevite dev
(this shows that vanillavite dev
is not vulnerable, providedhtmlFallbackMiddleware
is used)Detailed Impact
This will probably predominantly affect development-mode SSR, where
vite.transformHtml
is called using the originalreq.url
, per the docs:https://github.com/vitejs/vite/blob/7fd7c6cebfcad34ae7021ebee28f97b1f28ef3f3/docs/guide/ssr.md?plain=1#L114-L126
However, since this vulnerability affects
server.transformIndexHtml
, the scope of impact may be higher to also include other ad-hoc calls toserver.transformIndexHtml
from outside of Vite's own codebase.My best guess at bisecting which versions are vulnerable involves the following test script
and using it I was able to narrow down to #13581. If this is correct, then vulnerable Vite versions are 4.4.0-beta.2 and higher (which includes 4.4.0).
Release Notes
vitejs/vite (vite)
### [`v4.5.1`](https://togithub.com/vitejs/vite/releases/tag/v4.5.1) [Compare Source](https://togithub.com/vitejs/vite/compare/v4.5.0...v4.5.1) Please refer to [CHANGELOG.md](https://togithub.com/vitejs/vite/blob/v4.5.1/packages/vite/CHANGELOG.md) for details.Configuration
📅 Schedule: Branch creation - "" (UTC), Automerge - At any time (no schedule defined).
🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.
♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.
🔕 Ignore: Close this PR and you won't be reminded about this update again.
This PR has been generated by Mend Renovate. View repository job log here.