Esbuild is a blazing-fast JavaScript bundler and minifier, and comparing versions 0.5.23 and 0.5.24 reveals subtle but important considerations for developers. Both versions share identical descriptions, licensing under MIT, and repository details, confirming a consistent commitment to open-source principles and maintainability. Crucially, the distributed archive structure remains the same as well. Both versions have the same 'fileCount' of 6 and 'unpackedSize' of 21950.
The primary distinction lies in their release dates. Version 0.5.24 was published on July 7, 2020, at 00:40:34.817Z, while version 0.5.23 was released on July 6, 2020, at 10:01:33.897Z. This indicates that version 0.5.24 likely contains bug fixes, minor enhancements, or possibly performance tweaks implemented since the previous release. While the specific changes aren't detailed in this metadata, developers should consider this newer version for its potential improvements and stability.
When deciding which version to integrate, developers should prioritize checking the official esbuild changelog or release notes for detailed explanations of the updates included in version 0.5.24. Investigating these changes before upgrading ensures compatibility and enables leveraging any new features or addressing resolved issues. Using the latest stable minor version is often preferable, assuming it doesn't introduce unintended breaking changes into your build pipeline, which should be verified by the project maintainer.
All the vulnerabilities related to the version 0.5.24 of the package
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.