Tsup version 5.6.3 is a minor release over 5.6.2, both are modern bundlers powered by esbuild, designed for zero-config TypeScript packaging. They are aimed at simplifying the process of creating optimized and efficient JavaScript libraries and applications. Both versions support features such as automatic externalization of peer dependencies, code splitting, and generation of declaration files, making them appealing to developers who want a streamlined build process. Key dependencies like esbuild, rollup, and sucrase remain consistent between the versions, ensuring build stability.
A notable difference is the reduced unpacked size of v5.6.3. While minimal, it suggests subtle optimizations or changes in the packaging process. The release dates are also very close, indicating rapid iteration and bug fixes. For developers, upgrading to v5.6.3 is likely a safe bet, offering incremental improvements without major breaking changes. Both versions cater to developers seeking a fast, configuration-light build tool for their TypeScript projects, providing excellent support for various modern JavaScript features and module formats. They include peer dependency of Typescript version 4.2.3 and above. Both versions have a MIT License and are published by EGOIST.
All the vulnerabilities related to the version 5.6.3 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.