Tsup, a zero-config TypeScript bundler powered by esbuild, offers developers a streamlined approach to bundling TypeScript libraries. Examining versions 3.4.0 and 3.4.1 reveals subtle changes that may impact users. Both versions share identical dependencies for core functionality, including cac for command-line argument parsing, rollup for bundling, esbuild for fast builds, and sucrase for alternative TypeScript parsing. Development dependencies, crucial for building and testing the package itself, also remain the same across both versions. These include testing frameworks like jest and ts-jest, utility libraries such as fs-extra and fast-glob, and type definition packages. The crucial difference lies in the dist object, specifically the unpackedSize. Version 3.4.1 boasts a slightly increased unpacked size of 684,956 bytes compared to 3.4.0's 684,924 bytes, indicating a minor adjustment within the compiled output or bundled files. The release date of 3.4.1 is also a few hours after 3.4.0. This suggests bug fixes or very minor code improvements. For developers, this implies a potentially more stable version with enhanced performance or edge-case resolution. While the package contents seem almost identical, its highly advisable for users of 3.4.0 to update to version 3.4.1 to ensure they are running the most up-to-date and potentially improved iteration of the tool.
All the vulnerabilities related to the version 3.4.1 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.