Tsup version 3.2.0 introduces a few key updates compared to the previous stable version, 3.1.2, primarily focusing on dependency upgrades. For developers leveraging Tsup to bundle their TypeScript libraries, these changes bring subtle but potentially impactful improvements to the build process. The most notable change is the upgrade of esbuild from version 0.6.4 to 0.6.6. Esbuild being the core bundler that drives Tsup, any enhancement in esbuild directly translates to build performance and potential bug fixes. While the shift might seem incremental, esbuild updates often include optimizations in bundling speed and improved ES module support, crucial for modern JavaScript development.
Beyond esbuild, the dependency list remains largely consistent. This indicates a focus on stability and reliability. The core functionalities and Tsup’s approach to zero-config TypeScript bundling are preserved. Developers already familiar with Tsup 3.1.2 will find the upgrade to 3.2.0 seamless. They benefit from esbuild improvements without needing to adapt to significant configuration alterations or workflow changes. Other dependencies stay consistent giving confidence when upgrading. To upgrade just run your package manager upgrade command.
All the vulnerabilities related to the version 3.2.0 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.