Tsup is a blazing fast bundler powered by esbuild, designed for modern TypeScript and JavaScript projects. Version 3.8.0 arrived on November 12, 2020, succeeding version 3.7.1 released on October 25, 2020. While both versions share the same core dependencies like cac, chalk, globby, joycon, esbuild, sucrase, chokidar, resolve-from, and rollup-plugin-dts, their development dependencies and the precise versions of a few core dependencies showcase some interesting differences.
Notably, rollup saw an update from version 2.32.0 to 2.33.1 in the newer release, suggesting possible bug fixes or performance improvements in the bundling process. The jest testing framework was bumped from 26.6.0 to 26.6.3. Another relevant update for developers is the execa dependency, a process execution library, which moved from version 4.0.3 to 4.1.0. These upgrades indicate refinements in the testing and execution environments which provides a better integration inside the tooling.
Furthermore, the @types/node definition versions were slightly different, with v3.7.1 using 14.11.10 and v3.8.0 using 14.14.7, this may resolve compatibility in different Node environments. The unpacked size of the package also marginally increased from 577557 bytes to 578137, reflecting these code changes. Developers should consult the changelog for a comprehensive understanding of the exact changes introduced and if some of these have impact on the update path.
All the vulnerabilities related to the version 3.8.0 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.