Tsup, a zero-config TypeScript bundler powered by esbuild, released version 4.8.18 shortly after 4.8.17, showcasing rapid iteration. While both share the same core dependencies and development dependencies, indicating a consistent set of tools used for building and testing, a few key differences exist. The most noticeable change is the releaseDate, with version 4.8.18 being released on March 19, 2021, and version 4.8.17 on March 18, 2021. This suggests a quick fix or minor enhancement rolled out in the newer version. The unpackedSize also saw a slight increase from 757650 to 757909, indicating a small addition or modification to the bundled code.
For developers, this jump signals a potential bug fix that addresses specific edge cases discovered shortly after the previous release. Both releases continue to leverage a robust ecosystem including Rollup, esbuild, and Sucrase for optimized builds. The inclusion of PostCSS support is enhanced by postcss-load-config and postcss-simple-vars, providing developers with flexible CSS processing capabilities. The consistent peer dependency on TypeScript version 4.2.3 across both versions ensures compatibility with a specific TypeScript version. Developers should assess if the incremental changes address any specific issues they might have encountered with the previous sub-version.
All the vulnerabilities related to the version 4.8.18 of the package
tsup DOM Clobbering vulnerability
A DOM Clobbering vulnerability in tsup v8.3.4 allows attackers to execute arbitrary code via a crafted script in the import.meta.url to document.currentScript in cjs_shims.js components
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.