Tsup is a zero-config TypeScript bundler powered by esbuild, designed for speed and simplicity. Comparing versions 5.2.1 and 5.2.0 reveals subtle but potentially important changes. Developers considering an upgrade should be aware that the core functionalities appear consistent. The dependency lists remain largely unchanged, with identical versions for crucial tools like esbuild, rollup, typescript, and other build and testing utilities.
The key difference lies in the dist section of the package metadata. Version 5.2.1 indicates a slightly larger unpacked size (2921542 bytes) compared to 5.2.0 (2921158 bytes). This suggests minor internal adjustments or additions, perhaps involving documentation updates, internal code refactoring, or very small bug fixes. Moreover, version 5.2.1 was released two days later.
While these differences are minor, users should check the project's changelog or release notes for comprehensive details on what was addressed between these versions. For most developers, the upgrade from 5.2.0 to 5.2.1 should be seamless, but thorough testing is always recommended after any package update to ensure compatibility and stability within your project's specific context. Especially when dealing with build tools, even small changes can sometimes have unforeseen consequences in complex projects.
All the vulnerabilities related to the version 5.2.1 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.