Esbuild version 0.8.11 represents a minor iteration over the preceding 0.8.10 in this blazingly fast JavaScript bundler and minifier's evolution. Both versions maintain the same core attributes: MIT licensing, indicating freedom for commercial and private use, and accessibility through the established GitHub repository. The distributable package structure remains consistent with a compressed tarball format containing six files and an unpacked size of 50,882 bytes for both versions.
The key distinction lies in the release date timestamp. Version 0.8.11 was published on November 18, 2020, at 22:25:43.102Z, approximately 17 hours after version 0.8.10 which arrived at 05:13:11.574Z on the same day. While the lack of explicitly declared changes (e.g., in a changelog) hinders precise identification, developers can infer the update potentially include bug fixes, performance enhancements, or minor feature refinements implemented within that timeframe.
For developers seeking a reliable JavaScript bundler and minifier, Esbuild offers substantial speed advantages. Esbuild's speed makes it good to bundle and minify large codebases quicker. While the differences between versions 0.8.10 and 0.8.11 appear minimal, staying updated with the latest stable version is generally advisable to benefit from any cumulative improvements.
All the vulnerabilities related to the version 0.8.11 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.