Esbuild 0.14.17 is a patch release focusing on refinements to the blazing-fast JavaScript and CSS bundling and minification capabilities of the esbuild library. Compared to version 0.14.16, the dependencies have been updated to version 0.14.17, reflecting internal improvements and bug fixes across various platforms like Linux, macOS (Darwin), Windows, and various architectures including ARM, x64, and others. Developers leveraging esbuild will benefit from the cumulative enhancements incorporated into these platform-specific packages.
While the core description and functionality of esbuild remain consistent – providing an extremely fast build process – the key difference lies in the under-the-hood refinements. The "releaseDate" field indicates a newer release date for 0.14.17, suggesting recent improvements. Developers who prioritize stability and the latest bug fixes should upgrade to 0.14.17. The "unpackedSize" is marginally different, suggesting small changes in the bundled assets, possibly due to optimized code or updated dependencies. Projects already using esbuild can seamlessly upgrade to benefit from these latest improvements, ensuring they are using the most refined and stable version of this build tool. Always consider the package's release date and the fixes it may contain for optimal integration.
All the vulnerabilities related to the version 0.14.17 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.