WideLeak: How Over-the-Top Platforms Fail in Android

Nowadays, most content providers rely on DRM (Digital Right Management) to protect media from illegal distribution. Becoming a major platform for streaming, Android provides its own DRM framework that does not comply with existing DRM standards. Thus, OTT (over-the-top) platforms need to adapt their apps to suit Android design, despite a fragmented ecosystem and little public documentation. Unfortunately, the security implications of how OTT apps leverage Widevine, the most popular Android DRM, have not been studied yet. In this paper, we report the first experimental study on the state of Widevine use in the wild. Our study explores OTT compliance with Widevine guidelines regarding asset protection and legacy phone support. With the evaluation of premium OTT apps, our experiments bring to light that most apps adopt weak and potentially vulnerable practices. We illustrate our findings by showing how to easily recover media content from many OTT apps, including Netflix.