The quest for ring 0

All x86 CPUs in modern systems (Intel, AMD, etc.) have a feature that could be exploited on some operating systems to take total control of that system. Interestingly, modern versions of Windows actually aren’t vulnerable to this type of attack because of their implementation of a hardware abstraction layer or HAL. There are also ways to harden other OSs against this sort of attack, but it’s more a matter of mitigation than prevention.