Tsup version 6.1.1 represents a minor update over 6.1.0, focusing on refinements and under-the-hood improvements. While the core functionality remains consistent, developers should note the key distinctions. In the dependencies, version 6.1.1 introduce the "source-map": "0.8.0-beta.0" and "bundle-require": "^3.0.2" that weren't present in 6.1.0, this can improve speed and debugging capabilities. Conversely, version 6.1.0 included "string-argv":"0.3.1" in devDependencies, which is no longer present in the newer version, suggesting a potential shift in internal tooling or dependency management. Both versions share a similar set of peer dependencies, including postcss, @swc/core, and typescript, ensuring compatibility with existing projects utilizing these tools. Developers relying on specific developer tools might find minor differences in the bundled devDependencies which may affect local development workflows, testing, or build processes. Importantly, the unpacked size of the package has slightly decreased, indicating potential optimizations in the package structure. The release date highlights that 6.1.1 came out shortly after, suggesting a quick patch or minor feature addition. Overall, the update appears incremental, but prudent developers benefit from reviewing the changes to avoid unforeseen issues to ensure a smooth transition within their projects.
All the vulnerabilities related to the version 6.1.1 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.