tsup is a zero-config TypeScript bundler powered by esbuild, designed for creating modern JavaScript libraries. Version 4.9.1, released on April 19, 2021, is a minor update compared to the previous stable version 4.9.0, released just a day prior on April 18, 2021. Both versions maintain the core functionality of tsup, enabling developers to bundle TypeScript code effortlessly.
A subtle difference lies in the package size, where version 4.9.1 has a slightly smaller unpacked size of 840755 bytes compared to version 4.9.0's 840909 bytes. While seemingly insignificant, this could reflect minor optimizations or dependency adjustments within the build process.
The dependency and devDependency lists appear largely unchanged between the releases. Notably, both versions rely on esbuild 0.11.12, rollup 2.45.2 and Sucrase 3.18.1 for core bundling tasks. The peer dependency on TypeScript remains at "^4.2.3".
For developers, this suggests a seamless upgrade path from 4.9.0 to 4.9.1. The update most likely addresses bug fixes, performance tweaks, or minor compatibility improvements without introducing breaking changes. Users can expect consistent behavior and functionality between the two versions. Choosing the latest version is always recommended to have the latest fixes and improvements.
All the vulnerabilities related to the version 4.9.1 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.