Are Chrome Extensions Compliant with the Spirit of Least Privilege?


Extensions are small applications that are installed by users and enrich the user experience of browsing on the Internet. Browsers expose a set of restricted APIs to extensions where to be used, extensions need to list the permissions associated with these APIs in a mandatory file of the extension named manifest. In particular, Chrome’s permission ecosystem was designed in the spirit of the least privilege. Yet, this paper demonstrates that 39.8% of the analyzed extensions provided by the official WebStore are compliant with the spirit of least privilege. Also, we develop: 1) a browser extension to aware regular users of the permissions the extensions they install; a web app where extensions developers can check whether their extensions are compliant with the spirit of the least privileged, and; 3) a set of scripts that can be part of the vendors’ acceptance criteria such that when developers upload their extensions to the official repositories, the scripts automatically analyze the extensions and generate a report about the permissions and the usage.

International Journal of Information Security