Tsup, a zero-config TypeScript bundler powered by esbuild, released version 6.2.2, following closely on the heels of 6.2.1. The key update lies in the esbuild dependency, which jumps from version 0.14.25 to 0.15.1. This potentially unlocks new features and performance improvements from esbuild itself, benefitting developers using Tsup for their TypeScript library builds.
While most other dependencies remain consistent between the two versions, including core tools like rollup, sucrase, and chokidar, the vitest dev dependency also sees an update, moving from 0.19.0 to 0.21.1. This update probably includes new features, resolved issues and also performance enhancement of the vitest library.
Beyond dependency tweaks, the package sizes are subtly different; 6.2.2 shows a slight increase in unpacked size (475159 bytes) compared to 6.2.1 (474974 bytes). This may reflect the changes within the upgraded esbuild library or other minor adjustments. Developers should note that while the file count remains the same, these minor size variances could impact build times or bundle sizes in certain scenarios. The release date difference between the two versions are less than two weeks which means that this new release can be considered a patch release.
All the vulnerabilities related to the version 6.2.2 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.