The Rowhammer attack involves executing a malicious application that repeatedly accesses the same "row" of transistors on a memory chip in a tiny fraction of a second in a process called "Hammering."
As a result, hammering a memory region can disturb neighboring row, causing the row to leak electricity into the next row which eventually causes a bit to flip. And since bits encode data, this small change modifies that data, creating a way to gain control over the device.
In short, Rowhammer is an issue with new generation DRAM chips in which repeatedly accessing a row of memory can cause "bit flipping" in an adjacent row that could allow anyone to change the value of contents stored in the memory.
Rowhammer vulnerability for mobile devices has been reported first by vusec
This vulnerability has been marked as critical by Google and assigned CVE-2016-6728 by Google and Google is expected to release a patch in November. Due to the nature of attack – exploiting a hardware vulnerability – implementing comprehensive patch is not easy according to vusec
Rowhammer RAM attack for rooting Android devices, and can even be combined with existing Android vulnerabilities such as Bandroid and Stagefright. This means that an app having no permissions can potentially root Android device (see vusec paper, which also has videos demonstrating this )
How do I test if my device is affected?
An android app Drammer (Deterministic RowhAMMER) has been developed by vusec and can be side loaded. (See edit )
The app does not give you a nice popup that tells you whether you are vulnerable or not. You can easily spot induced bit flips by glancing over the output and looking for the obvious keyword FLIP. Sample output from my device below
Your phone might still be vulnerable, even if the app detected zero flips! Because of current implementation of app and it may not have fully tested memory , which implies results may not be conclusive