Power Analysis Pushed too Far: Breaking Android-Based Isolation with Fuel Gauges.

Efficient power management is critical for embedded devices, both for extending their lifetime and ensuring safety. However, this can be a challenging task due to the unpredictability of the batteries commonly used in such devices. To address this issue, dedicated Integrated Circuits (ICs) known as “fuel gauges” are often employed outside of the System-on-Chip (SoC). These devices provide various metrics about the available energy source and are highly accurate. However, their precision can also be exploited by malicious actors to compromise platform confidentiality if the Operating System (OS) fails to intervene. Depending on the fuel gauge and OS configuration, several attack scenarios are possible. In this article, we focus on Android and demonstrate how it is possible to bypass application isolation to recover Personal Identification Numbers (PINs) entered in other processes.