Tsup is a zero-config TypeScript bundler powered by esbuild, designed for creating modern JavaScript libraries. Version 4.8.21 arrives shortly after 4.8.20, both maintaining the core functionality that developers appreciate: effortless bundling, automatic declaration file generation, and support for various modern JavaScript features. Dependencies like cac, chalk, debug, esbuild, rollup and sucrase remain consistent, ensuring a reliable build process. Similarly, development dependencies such as jest, prettier, and @types/node are unchanged, indicating a focus on stability and developer experience. The peer dependency on typescript at version ^4.2.3 ensures compatibility with existing TypeScript projects.
While the core functionality remains the same, some minor underlying changes have occurred. Version 4.8.21 features a slightly larger unpacked size (837237 bytes vs 836689 bytes in 4.8.20), which might indicate small updates to internal modules, dependency tweaks or other minor refinements. The release date for 4.8.21 is also later, suggesting a quick follow up to address a specific bug or improvement. For developers, this suggests a healthy and actively maintained project. Upgrading from 4.8.20 to 4.8.21 is likely a low-risk operation focused on getting the latest fixes, if any, rather than introducing major new features. If you want a fast and easy way to bundle your typescript code, Tsup is a good option for Javascript libraries.
All the vulnerabilities related to the version 4.8.21 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.