Tsup, a zero-config bundler powered by Rollup and esbuild, released versions 1.4.19 and 1.4.18 in quick succession. While seemingly minor, a closer look reveals key updates that impact developers. The most notable change lies within the dependencies. Version 1.4.19 upgrades rollup from version 2.10.3 to 2.12.0. This update within Rollup could bring performance enhancements, bug fixes, and potentially new features to the bundling process, translating to faster build times and improved output for users of Tsup.
Both versions retain the same core dependencies and devDependencies, including rollup-plugin-dts for generating declaration files, rollup-plugin-esbuild for speedy transpilation, and essential tools like TypeScript, Jest, and Prettier for development and testing. This consistency ensures a smooth upgrade process.
The dist object in the package metadata also shows small differences. Version 1.4.19 has a slightly increased unpacked size of 336187 bytes, up from 336090 bytes in version 1.4.18, due to the Rollup update. The release dates show versions released within minutes so the Rollup upgrade was likely essential but backwards compatible fix (likely bug). For developers already using Tsup, upgrading to 1.4.19 is recommended to leverage the latest Rollup improvements. For new users, starting with the newest version ensures leveraging all the enhancements from the start. Tsup simplifies modern web development and building JS libraries by removing configuration headaches.
All the vulnerabilities related to the version 1.4.19 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.