Tsup is a zero-config TypeScript bundler leveraging the speed of esbuild, designed to simplify the process of packaging TypeScript libraries. Comparing versions 3.4.2 and 3.4.1, the core functionality remains consistent, but subtle underlying changes are present. Both versions share the same dependencies, including tools like cac for command-line argument parsing, chalk for stylized console output, joycon for configuration management, rollup for module bundling, esbuild for its lightning-fast builds, sucrase for alternative TypeScript parsing, chokidar for file watching, and rollup-plugin-dts for generating declaration files. The developer dependencies are identical too, including testing with jest and ts-jest, utilities such as fs-extra and fast-glob, formatting with prettier, and type definitions for various packages.
A key difference lies in the dist section, specifically the unpackedSize. Version 3.4.2 has an unpacked size of 685346 bytes, while version 3.4.1 has 684956 bytes. This indicates a slight increase in the size of the installed package, potentially due to minor code adjustments, updated dependencies (though not reflected in the declared dependency versions), or changes in the build process. Furthermore, the release dates differ by a few minutes. Developers should be aware of this size difference if package size is a concern also verify the potencial bugfixes done between versions, while the core functionalities for bundling TypeScript libraries remain the same emphasizing Tsup is optimized for speed and ease of use.
All the vulnerabilities related to the version 3.4.2 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.