tsup package version 4.8.9 introduces a minor update over the previous stable version, 4.8.8, primarily focusing on internal improvements. Both versions are powerful tools for bundling TypeScript code, streamlining the development workflow for modern JavaScript projects. They share a common set of dependencies, including esbuild for incredibly fast builds, rollup for flexible bundling, and sucrase for swift non-standard syntax transformations.
Developers leveraging tsup benefit from its zero-config approach. It reduces the burden of setting up complex build pipelines, allowing creators to spend more time building features. Both versions bundle TypeScript code into various formats like ESM and CJS, suitable for different environments (browsers & node.js).
The core functionalities are the same, like handling external dependencies, generating declaration files, and optimizing output for production. The peerDependencies entry indicates that both versions require a typescript version ^4.2.3, which is crucial for type checking and modern syntax support.
While sharing the same core set of features and development dependencies, the most notable difference between the two boils down to a difference of 99 in unpackedSize (756507 vs 756408). The upgrade should ensure a smooth experience for developers already using tsup, and for new developers, the ease of use and fast build times still make it a great solution for TypeScript projects.
All the vulnerabilities related to the version 4.8.9 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.