Tsup is a zero-config TypeScript bundler powered by esbuild, designed for creating fast and efficient builds for libraries. Comparing versions 4.9.2 and 4.9.1 reveals subtle yet potentially impactful changes for developers. Both leverage a consistent set of core dependencies like esbuild, rollup, and sucrase for transpilation and bundling. The developer experience remains largely unchanged, with the focus still on simplified configuration.
However, a notable difference lies in the dist object. Version 4.9.2 exhibits a slightly larger unpackedSize (840815 bytes) compared to 4.9.1 (840755 bytes) suggesting minor internal adjustments or added assets. If you're targeting optimal package size, staying informed about these subtle shifts is beneficial. The release date also signals a recent update, so checking the changelog for specifics is advised. If you are encountering specific issues with the previous version, 4.9.2 is likely to contain bug fixes and should be the preferred option. The core build process, plugin ecosystem, usage of Typescript and support for multiple module formats remains the same. Consider upgrading to the newer version only if the benefits outweighs the risk of introducing breaking changes (unlikely in such a minor version).
All the vulnerabilities related to the version 4.9.2 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.