Tsup is a zero-config bundler powered by Rollup and ESBuild, designed to simplify the process of creating optimized JavaScript libraries. Comparing versions 1.4.3 and 1.4.2, the core functionality remains consistent, focusing on leveraging Rollup for bundling and ESBuild for incredibly fast builds. Both versions share the same dependencies, including joycon for configuration management, rollup for the core bundling process, and rollup-plugin-esbuild for rapid transpilation.
The devDependencies also remain identical, showcasing the continued use of testing frameworks like jest and ts-jest, utilities for file system manipulation (fs-extra), code formatting (prettier), and TypeScript support. The consistent development dependencies indicate a stable and mature development environment. From a developer’s perspective, upgrading from 1.4.2 to 1.4.3 should be seamless since the dependencies remain the same.
The primary difference lies in the package metadata: the releaseDate (just a few minutes apart) and a slight variation in unpackedSize and this is likely due to very minor adjustments in the build process or included documentation.
For developers already using Tsup, this update is likely a minor patch, that might contain minor bug fixes. For new users, either version 1.4.2 or 1.4.3 provides a solid foundation for bundling libraries, thanks to Tsup's straightforward, configuration-free approach and the speed of ESBuild. The core benefit is a streamlined bundling experience for modern JavaScript projects.
All the vulnerabilities related to the version 1.4.3 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.