Tsup is a zero-config TypeScript bundler powered by esbuild, designed for creating library packages. Comparing versions 5.4.2 and 5.4.1, developers will find subtle yet important variations impacting their workflow. Both versions share the same core dependencies like esbuild, rollup, and sucrase, ensuring consistent TypeScript compilation and bundling. However, version 5.4.2 introduces a notable change in its distribution package, containing 19 files with an unpacked size of 902955 bytes, while version 5.4.1 has 15 files and a significantly larger unpacked size of 2921105 bytes. This indicates that the newer version might have optimized its package structure and potentially reduced its overall footprint, leading to faster installation times and reduced disk space usage.
The rest of the dependencies and devDependencies seem to be exactly the same.
For developers, this means upgrading to 5.4.2 could streamline their development environment. The updated version was released on October 19, 2021, just two days after 5.4.1, suggesting a quick patch or refinement. Tsup simplifies the process of bundling TypeScript libraries with minimal configuration.
All the vulnerabilities related to the version 5.4.2 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.