50 Ways to Leak Your Data: An Exploration of Apps’ Circumvention of the Android Permissions System

Smartphones are general-purpose computers that store a great deal of sensitive personal information. Apps are prevented from accessing this information at will through the use of a permission system at the operating-system level. These security mechanisms are reasonable because we carry our smartphones alongside us all day, and they can gain access to our intimate communications and social network, our web browsing history, our location at all times—even if the GPS is disabled. When apps are denied permissions, however, they still have options to cheat the permission system by using side and covert channels. In our research we found a small number of such channels being actively exploited when we tested Google Play Store apps.