Tsup is a zero-config TypeScript bundler powered by esbuild, designed for creating modern JavaScript libraries with speed and simplicity. Version 5.4.3 builds on the solid foundation of 5.4.2, offering incremental improvements and refinements. While the core functionality remains consistent, several key aspects are worth noting for developers.
The dependency lists for both versions are nearly identical, meaning the fundamental tools used by Tsup haven't significantly changed. This indicates a focus on stability and optimization rather than radical feature additions. Both rely on robust packages like esbuild for blazing-fast bundling, Rollup for further processing, and Sucrase for alternative TypeScript transformations. This stability ensures a predictable and reliable build process.
A notable difference lies in the dist object. Version 5.4.3 has a slightly larger unpackedSize (904092 bytes) compared to 5.4.2 (902955 bytes). This suggests that 5.4.3 may include minor additions or adjustments to the bundled output. This could be from added documentation, updated default configurations, or optimized code. While seemingly small, these changes can contribute to improved performance or compatibility. The release dates also highlight the recency of version 5.4.3, indicating that it incorporates the latest fixes and enhancements. Developers should always strive to use the latest version for the best experience.
All the vulnerabilities related to the version 5.4.3 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.