Tsup is a zero-config TypeScript bundler powered by esbuild, designed to simplify the creation of TypeScript libraries. Version 8.0.0 introduces some changes compared to the previous stable version 7.3.0. The core functionalities remain consistent, focusing on fast and efficient bundling. Both versions share the same core dependencies like esbuild, rollup, and sucrase, ensuring consistent performance. However, there's a notable addition in version 8.0.0 of @microsoft/api-extractor as both a devDependency and a peerDependency, suggesting improved API extraction capabilities for generating declaration files. Noticeably, version 8.0.0 has an updated releaseDate and unpackedSize, now at 501149 bytes compared to 485920 bytes in version 7.3.0 indicating some internal modifications and/or additions.
Developers upgrading to 8.0.0 can expect potentially better generation of declaration files with enhanced API extraction. The library has been updated internally (as seen with the new unpackedSize) even if the core dependencies have not changed. Both versions ensure a straightforward bundling experience, abstracting away complex configurations while maintaining excellent performance. For developers requiring robust API extraction and declaration file generation alongside the core bundling features, upgrading to version 8.0.0 is recommended. Otherwise version 7.3.0 should be more than adequate, especially if they are concerned about package size.
All the vulnerabilities related to the version 8.0.0 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.