Esbuild version 0.14.45 represents a minor update over the previous stable release, 0.14.44, primarily focusing on internal improvements reflected in the incremented dependency versions. Developers should note that both versions share the same core functionality as an extremely fast JavaScript and CSS bundler and minifier. The key difference lies in the updated dependencies specific to different operating systems and architectures. Both versions include identical sets of dependencies and optional dependencies, covering a wide range of platforms from Linux (various architectures), macOS (x64 and ARM64), Windows (32-bit, 64-bit, and ARM64), to more niche systems like SunOS, NetBSD, FreeBSD, OpenBSD, and Android.
The update from 0.14.44 to 0.14.45 brings all of these platform-specific dependencies up to the 0.14.45 version, suggesting bug fixes or performance enhancements within esbuild's platform-specific compiled binaries. For developers, it means ensuring compatibility and potentially benefiting from the latest optimizations for their target deployment environment, although the core API and features remain consistent. The small difference in unpacked size hints at minor adjustments in the build process or binary sizes across these dependencies. Developers should always consult the official esbuild changelog for detailed information regarding specific fixes and enhancements included in the platform-specific dependencies. Using the latest version is generally recommended to leverage the most up-to-date improvements.
All the vulnerabilities related to the version 0.14.45 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.