Tsup version 2.1.0 introduces notable improvements over its predecessor, version 2.0.3, particularly in its core build process and supported features. The most significant change for developers is the shift to esbuild as the primary bundler, promising faster build times and a more streamlined experience. This contrasts with the previous version's reliance on rollup-plugin-typescript2. To support the new bundler, the package introduces the rollup-plugin-esbuild plugin and replaces tslib with esbuild as a needed dependency.
Furthermore, version 2.1.0 brings updated dependencies, including newer versions of rollup, cac, and rollup-plugin-dts, likely incorporating bug fixes, performance enhancements, and new features from these libraries. Notably, several development dependency versions are also updated that seems to solve compatibility issues. The small difference on the unpackedSize size from the tarball may be related to those changes, but in general the final goal of the library stay the same: Rollup your TypeScript library with no config. This upgrade aims to provide a smoother and more efficient build process for TypeScript libraries, making tsup an even more attractive choice for developers seeking a zero-config bundling solution.
All the vulnerabilities related to the version 2.1.0 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.