Tsup version 6.6.3 introduces subtle but potentially important updates compared to version 6.6.2. Examining the package metadata reveals that rollup-plugin-dts has been bumped from version 5.1.0 to 5.2.0 in the devDependencies, which could bring improvements or bug fixes related to generating TypeScript declaration files. The dist object shows a slight increase in unpackedSize from 503655 to 509901, indicating code additions or modifications. This could mean updated features, improved performance or adjustments in the build process.
Developers should note the release date difference, with 6.6.3 deployed just two days after 6.6.2. It's a minor release which implies that the new version provides bug fixes or minor improvements rather than significant new features. As tsup aims at simplifying TypeScript library bundling with zero-config and esbuild power, even small increments can enhance developer experience. Using the newest rollup-plugin-dts plugin guarantees developers are using the latest tooling for type definition generation. Before upgrading developers need to acknowledge the increase in bundle size, which can hint at expanded functionalities or fixed previous issues in the module generation.
All the vulnerabilities related to the version 6.6.3 of the package
tsup DOM Clobbering vulnerability
A DOM Clobbering vulnerability in tsup v8.3.4 allows attackers to execute arbitrary code via a crafted script in the import.meta.url to document.currentScript in cjs_shims.js components
esbuild enables any website to send any requests to the development server and read the response
esbuild allows any websites to send any request to the development server and read the response due to default CORS settings.
esbuild sets Access-Control-Allow-Origin: * header to all requests, including the SSE connection, which allows any websites to send any request to the development server and read the response.
https://github.com/evanw/esbuild/blob/df815ac27b84f8b34374c9182a93c94718f8a630/pkg/api/serve_other.go#L121 https://github.com/evanw/esbuild/blob/df815ac27b84f8b34374c9182a93c94718f8a630/pkg/api/serve_other.go#L363
Attack scenario:
http://malicious.example.com).fetch('http://127.0.0.1:8000/main.js') request by JS in that malicious web page. This request is normally blocked by same-origin policy, but that's not the case for the reasons above.http://127.0.0.1:8000/main.js.In this scenario, I assumed that the attacker knows the URL of the bundle output file name. But the attacker can also get that information by
/index.html: normally you have a script tag here/assets: it's common to have a assets directory when you have JS files and CSS files in a different directory and the directory listing feature tells the attacker the list of files/esbuild SSE endpoint: the SSE endpoint sends the URL path of the changed files when the file is changed (new EventSource('/esbuild').addEventListener('change', e => console.log(e.type, e.data)))The scenario above fetches the compiled content, but if the victim has the source map option enabled, the attacker can also get the non-compiled content by fetching the source map file.
npm inpm run watchfetch('http://127.0.0.1:8000/app.js').then(r => r.text()).then(content => console.log(content)) in a different website's dev tools.Users using the serve feature may get the source code stolen by malicious websites.