Tsup is a zero-config TypeScript bundler powered by esbuild, designed for creating fast and efficient libraries. Comparing versions 5.4.1 and 5.4.0 reveals subtle yet impactful changes relevant to developers. Both versions share identical core dependencies and devDependencies, suggesting a focus on stability and refinement rather than radical feature additions. Key dependencies remain consistent, including Rollup for module bundling, esbuild for rapid transpilation, and Sucrase for alternative TypeScript/JavaScript dialect support. The peer dependency on TypeScript remains at "^4.2.3," ensuring compatibility for projects using TypeScript 4.2.3 or higher.
Differences emerge in the dist properties. While both versions exhibit similar file counts (15 vs 14) and unpacked sizes (2921105 vs 2921078 bytes), the slight adjustments hint at internal optimizations or minor bug fixes. A critical difference is the release date. Version 5.4.1 was released on October 17, 2021, approximately ten days after version 5.4.0, released on October 7, 2021. This suggests that version 5.4.1 is likely a patch or maintenance release addressing issues discovered in 5.4.0. Developers should upgrade to the latest version (5.4.1 in this case) to benefit from potential bug fixes, performance improvements, and enhanced stability. The consistent dependency list across versions indicates a reliable and mature tool for streamlined TypeScript bundling, making Tsup a solid choice for library authors prioritizing speed and ease of use.
All the vulnerabilities related to the version 5.4.1 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.