Esbuild version 0.15.10 represents a minor update over its predecessor, 0.15.9, in this extremely fast JavaScript and CSS bundler and minifier. Both versions maintain the same core functionality and licensing under the MIT license. The manifest differences are reflected in minimal metadata revisions. A key aspect for developers to note is the update to the sub-dependencies of specific platform-targeted builds with the newer version now requiring "0.15.10" rather than "0.15.9". This change ensures consistent versioning across the entire dependency tree, potentially addressing underlying bug fixes or performance improvements within these specific platform builds. These platforms range from various Linux architectures(32-bit, 64-bit, ARM, ARM64, s390x, ppc64le, riscv64, mips64le, loong64), Windows (32-bit, 64-bit, ARM64), macOS (64-bit, ARM64), and other operating systems like SunOS, NetBSD, FreeBSD, OpenBSD and Android. The unpacked size of the new version is slightly larger, 120692 versus 120481, although this difference is negligible. Developers should update to version 0.15.10 to stay current with the latest refinements, especially if cross-platform compatibility or specific architecture optimizations are critical to their project. In both versions, dependencies are mirrored in optionalDependencies, meaning there are no additional dependencies.
All the vulnerabilities related to the version 0.15.10 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.