Tsup is a zero-config TypeScript bundler powered by esbuild, designed for creating modern JavaScript libraries. Comparing versions 4.8.15 and 4.8.16, the core functionalities remain consistent, offering developers a streamlined build process for TypeScript projects. Both versions share the same dependencies, including essential tools like esbuild for incredibly fast builds, rollup for bundling, sucrase for faster non-type-checking transpilation and chokidar for file watching. Development dependencies are also identical, encompassing testing frameworks like jest and ts-jest, along with tools for linting, formatting (Prettier), and type checking (TypeScript).
The key difference between the two versions lies in their release date and potentially very minor bug fixes or internal improvements, with version 4.8.16 released approximately 30 minutes after 4.8.15. While the specific nature of these changes isn't explicitly detailed in the provided data, developers can generally expect patch releases like this to address smaller issues without introducing breaking changes.
For developers using Tsup, both versions offer a robust and efficient solution for bundling TypeScript code. The zero-config approach simplifies the build process, allowing developers to focus on writing code rather than configuring complex build tools. Tsup's speed, thanks to esbuild, significantly reduces build times, improving developer productivity. It allows for building libraries for different platforms (CJS, ESM, IIFE), generating declaration files and it’s well-documented and easy to integrate into existing projects. When upgrading between minor versions like these, it's always advisable to review the changelog for any specific fixes or improvements that might impact your project.
All the vulnerabilities related to the version 4.8.16 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.