Jack-in-the-box: An Empirical Study of JavaScript Bundling on the Web and its Security Implications
Jeremy Rack, Cristian-Alexandru Staicu · 2023
In recent years, we have seen an increased interest in studying the software supply chain of user-facing applications to uncover problematic third-party dependencies. Prior work shows that web applications often rely on outdated or vulnerable third-party code. Moreover, real-world supply chain attacks show that dependencies can also be used to deliver malicious code, e.g., for carrying cryptomining operations. Nonetheless, existing measurement studies in this domain neglect an important software engineering practice: developers often merge together third-party code into a single file called bundle, which they then deliver from their own servers, making it appear as first-party code. Bundlers like Webpack or Rollup are popular open-source projects with tens of thousand of GitHub stars, suggesting that this technology is widely-used by developers. Ignoring bundling may result in underestimating the complexity of modern software supply chains.