Esbuild is a blazing-fast JavaScript bundler and minifier, and versions 0.12.13 and 0.12.14 offer developers efficient tools for optimizing their web development workflows. Both versions share the same core features: rapid bundling, minification, and support for modern JavaScript syntax. They are licensed under the MIT license and are hosted on GitHub. Both versions have a file count of 6 and an unpacked size of 88700.
The key distinction between these two versions lies in their release dates. Version 0.12.13 was released on July 1st, 2021 at 06:21 UTC, while version 0.12.14 was published later that same day at 23:30 UTC. While the core functionality remains consistent, the rapid subsequent release suggests the possibility of bug fixes or minor improvements implemented in version 0.12.14 following the initial 0.12.13 release.
For developers, this means that while both versions are reliable choices, opting for the slightly newer 0.12.14 is generally advisable. It could potentially include crucial patches or refinements that enhance stability or address unforeseen issues discovered shortly after the 0.12.13 release. Always consult the official esbuild changelog or release notes for detailed information on specific changes introduced between these versions to make an informed decision for your project. When speed and efficiency are paramount, esbuild continues to be an excellent choice for JavaScript bundling and minification.
All the vulnerabilities related to the version 0.12.14 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.