Tsup is a zero-config TypeScript bundler powered by esbuild, designed for creating modern JavaScript libraries. Comparing versions 5.4.4 and 5.4.3, the core functionalities remain consistent, but subtle changes might impact developers. Both versions share the identical set of dependencies and devDependencies, so no new features or breaking changes are available at first sight regarding these tools. This translates to a stable development experience, where upgrades won't force developers to rewrite their build configurations. The peer dependency remains the same, typescript version ^4.2.3, therefore there are no changes to the support to typescript versions. The fileCount and unpackedSize present in the dist object are very similar, meaning that this is probably bug fixes and small improvements. The release date shows that just one day passed between both releases. The latest version, 5.4.4, was released on October 24, 2021, subsequent to version 5.4.3 released on October 22, 2021.
Given the minimal differences and rapid release cycle, version 5.4.4 likely addresses bug fixes or internal improvements discovered shortly after the 5.4.3 release. For developers, upgrading to the latest patch version is generally recommended to benefit from these refinements. However, in this case, the changes are so small that both versions can be considered equally stable, and for most developers, upgrading is not mandatory. As always, examine the changelog for a detailed account of the alterations.
All the vulnerabilities related to the version 5.4.4 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.