"rowhammer", rapidly writes and rewrites memory to force capacitor errors in DRAM, which can be exploited to gain control of the system. By repeatedly recharging one line of RAM cells, bits in an adjacent line can be altered, thus corrupting the data stored.

This corruption can lead to the wrong instructions being executed, or control structures that govern how memory is assigned to programs being altered – the latter case can be used by a normal program to gain kernel-level privileges.

via Ouch! Google crocks capacitors and deviates DRAM to root Linux • The Register.