Esbuild versions 0.6.22 and 0.6.23 represent incremental updates to a high-performance JavaScript bundler and minifier designed for speed and efficiency. Both versions share the same core characteristics: they are licensed under the MIT license, feature the same description as "An extremely fast JavaScript bundler and minifier", and originate from the same GitHub repository. They also have the same number of files(6) and same unpacked size (32114).
The primary differentiator between these releases lies in their release dates. Version 0.6.23 was published on August 14, 2020, at 07:26:15.591Z, while version 0.6.22 was released a day earlier on August 13, 2020, at 08:50:07.249Z. This 1-day gap suggests that version 0.6.23 likely includes bug fixes, minor enhancements, or internal improvements made after the release of 0.6.22.
For developers, this means choosing between the two depends on their tolerance for potentially undiscovered issues in the newer release. If stability is paramount, sticking with version 0.6.22 might be preferable. However, developers eager to leverage the latest refinements and bug fixes should opt for version 0.6.23. Given the minimal time difference, the upgrade risk appears low, and adopting 0.6.23 is likely to provide a superior experience overall. Always consult the official esbuild changelog or release notes for detailed information on the precise changes between versions.
All the vulnerabilities related to the version 0.6.23 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.