Esno is a lightweight and fast TypeScript and JavaScript Node.js runtime powered by esbuild, designed for developers who value speed and simplicity. Comparing versions 0.16.1 and 0.15.0, the primary difference lies in the dependency updates. Version 0.16.1 upgrades the tsx dependency to ^3.0.0 from ^2.0.1 in version 0.15.0. This tsx update likely brings improvements and new features related to TypeScript execution and hot reloading capabilities, potentially enhancing the developer experience during development.
Notably, both versions share a similar set of development dependencies, including zx for scripting, fsxx which may provide extended filesystem functionalities, and typescript for type checking. They are licensed under MIT, inviting broad usage and contribution.
Developers considering Esno will appreciate its ability to quickly execute TypeScript and JavaScript code without the overhead of a full-fledged compilation process. This makes it ideal for rapid prototyping, testing, and running small scripts. The upgrade to tsx@3.0.0 in version 0.16.1 suggests improvements regarding compilation speeds, code compatibility and enhanced tooling making it a favourable update that should motivate migration to it. Consider checking the tsx changelog for a comprehensive overview of these advancements. Otherwise, both versions offer a streamlined and efficient way to run your code providing a compelling alternative to traditional Node.js workflows for TypeScript and Javascript projects.
All the vulnerabilities related to the version 0.16.1 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.