Tsup version 5.9.0 introduces subtle but potentially impactful changes compared to its predecessor, 5.8.1. Both versions share the same core dependencies like esbuild, rollup, and typescript, ensuring a consistent build process for modern JavaScript and TypeScript projects. The development dependencies also remain largely the same, suggesting a focus on maintaining the existing testing and development environment.
The key difference lies in the dist object. Version 5.9.0 presents a slightly larger unpackedSize of 875805 bytes compared to 5.8.1's 875025 bytes. While seemingly minor, this increase could hint at internal code optimizations or the addition of new features or assets within the package. Developers considering upgrading should be mindful of this slight size increase, particularly in resource-constrained environments.
Furthermore, the releaseDate indicates that version 5.9.0 was released shortly after 5.8.1. These small differences might suggest a bug fix or minor update. The package provides a streamlined build process with zero-config, transpiling, bundling, and packaging code. It supports various entry points, formats (ESM, CJS, IIFE), and target environments (Node.js, browser). It's suitable for library authors and application developers desiring a simple way to set up modern TypeScript project build.
All the vulnerabilities related to the version 5.9.0 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.