Tsup is a zero-config TypeScript bundler powered by esbuild, designed for creating modern JavaScript libraries. Comparing version 4.8.20 with the previous stable version 4.8.19, a key difference lies in the updated dependency on esbuild, which jumps from version 0.9.3 to 0.10.2. This potentially introduces new features, performance enhancements, and bug fixes inherent in the newer esbuild release, directly impacting the bundling speed and output quality. While other dependencies remain mostly consistent, the dist object shows a slightly larger unpacked size for version 4.8.20 (836689 bytes vs 831191 bytes), suggesting some internal changes or additions. This update warrants investigation by developers to ensure continued compatibility and potential performance improvements with their existing projects. The library simplifies the process of building TypeScript projects, optimizing for speed and ease of use. It's a valuable tool for developers aiming to publish high-quality, modern JavaScript packages without the complexities of manual configuration. This update promises an improved bundling experience through the upgrades on its internal esbuild dependency.
All the vulnerabilities related to the version 4.8.20 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.