Attacks on WebView in the Android system

Abstract

WebView is an essential component in both Android and iOS platforms, enabling smartphone and tablet apps to embed a simple but powerful browser inside them. To achieve a better interaction between apps and their embedded "browsers", WebView provides a number of APIs, allowing code in apps to invoke and be invoked by the JavaScript code within the web pages, intercept their events, and modify those events. Using these features, apps can become customized "browsers" for their intended web applications. Currently, in the Android market, 86 percent of the top 20 most downloaded apps in 10 diverse categories use WebView. The design of WebView changes the landscape of the Web, especially from the security perspective. Two essential pieces of the Web's security infrastructure are weakened if WebView and its APIs are used: the Trusted Computing Base (TCB) at the client side, and the sandbox protection implemented by browsers. As results, many attacks can be launched either against apps or by them. The objective of this paper is to present these attacks, analyze their fundamental causes, and discuss potential solutions.