Esbuild versions 0.1.10 and 0.1.11 are both iterations of the exceptionally fast JavaScript bundler and minifier, designed to drastically improve build times for web developers. While the core functionality remains consistent, some may wonder, what are the differences? Both versions maintain the same MIT license, ensuring freedom and flexibility for users. They share the same fundamental structure with a fileCount of 3 and an unpackedSize of 2463. They are both accessible via the same GitHub repository.
The primary distinction between these two versions lies in their respective release dates. Version 0.1.10 was released on April 18, 2020, while version 0.1.11 followed shortly after, on April 19, 2020. As such, version 0.1.11 likely incorporates bug fixes, minor optimizations, or very specific edge-case corrections identified after the release of 0.1.10. So far there have been no major API changes or new features.
For developers leveraging esbuild, deciding between 0.1.10 and 0.1.11 might depend on their specific needs and risk tolerance. Those seeking the absolute latest fixes and improvements would naturally prefer the newer version. If needing stability above all, consider exploring more recent versions since these versions are quite old.
All the vulnerabilities related to the version 0.1.11 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.