Esbuild version 0.14.7 represents a minor update to the extremely fast JavaScript and CSS bundler and minifier, building upon the solid foundation of version 0.14.6. Both versions share identical descriptions, dependencies, optional dependencies, license (MIT), and repository details, indicating no fundamental architectural changes or alterations to the core feature set. Developers relying on esbuild for its speed and efficiency in bundling and minifying assets can expect similar performance characteristics between the two versions.
The key difference lies within the version numbers of the core package and its platform-specific dependencies. All dependencies and optional dependencies, such as esbuild-linux-64 and esbuild-darwin-arm64, are bumped from version 0.14.6 to 0.14.7 to match the main package version. This suggests that the update likely includes bug fixes, performance improvements, or minor adjustments within these platform-specific binaries. Crucially, developers should note the difference in release dates: 0.14.7 came out on December 21, 2021, while 0.14.6 was released on December 20, 2021.
For developers, this minor version bump signifies stability and a continued commitment to maintenance. While the unpacked size and file structure remain consistent, the updated dependencies imply a refinement of the existing functionalities, potentially addressing edge cases or enhancing performance on specific operating systems and architectures. Users are encouraged to upgrade to version 0.14.7 to benefit from these refinements and ensure compatibility across different deployment environments. Although the changelog is not provided here. Checking it on the related github repo of esbuild is recommended to have a better understanding.
All the vulnerabilities related to the version 0.14.7 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.