Time Does Not Heal All Wounds: A Longitudinal Analysis of Security-Mechanism Support in Mobile Browsers

Abstract

Recent market share statistics show that mobile device traffic has overtaken that of traditional desktop computers. Users spend an increasing amount of time on their smartphones and tablets, while the web continues to be the platform of choice for delivering new applications to users. In this environment, it is necessary for web applications to utilize all the tools at their disposal to protect mobile users against popular web application attacks. In this paper, we perform the first study of the support of popular web-application security mechanisms (such as the Content-Security Policy, HTTP Strict Transport Security, and Referrer Policy) across mobile browsers. We design 395 individual tests covering 8 different security mechanisms, and utilize them to evaluate the security-mechanism support in the 20 most popular browser families on Android. Moreover, by collecting and testing browser versions from the last seven years, we evaluate a total of 351 unique browser versions against the aforementioned tests, collecting more than 138K test results.