Tsup version 6.2.0 arrives as a refined iteration of the popular zero-config bundler, building upon the solid foundation laid by version 6.1.3. While the core functionality remains consistent, a key difference lies in the updated dependencies, particularly within the development environment. Notably, @swc/core sees a significant jump from version 1.2.126 to 1.2.218, suggesting improvements or bug fixes within the Speedy Web Compiler that Tsup leverages for its lightning-fast builds. Furthermore, vitest, the blazing-fast unit test framework, advances from version 0.8.4 to 0.19.0, providing developers with access to enhanced testing capabilities and potentially a more stable testing environment.
The update to esbuild from '^0.14.25', indicates that the core bundling engine has been kept up to date. For developers, this translates to potentially faster build times, improved compatibility with newer JavaScript features, and access to the latest bug fixes and performance enhancements within these underlying tools. While the core dependencies remain largely unchanged, the subtle shifts in the development dependencies reflect a commitment to maintaining a modern and efficient development workflow. TypeScript remains consistent at v4.6.3, ensuring familiarity and stability in projects using this superset of JavaScript. It's essential for users to review the changelogs of the updated development dependencies, especially @swc/core and vitest, to understand the specific changes and potential impact on their projects when upgrading to version 6.2.0. source-map is also updated from '0.7.4' to "0.8.0-beta.0", thus providing a more debug friendly experience.
All the vulnerabilities related to the version 6.2.0 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.