Many cybersecurity exploits have been deemed The One Ring To Rule Them All, but that moniker is rarely as true as a literal bit that disables the memory mapping on some AMD CPUs, granting access to normally inaccessible areas. With just one instruction, you can access off-limits software like Platform Security Processor (PSP) where the TPM runs, the System Management Mode (SMM), microcode patch RAM, and other various sundries — in other words, full hardware-level control.
The exploit is called Skitter Creek Bath Salts (Skitter), and was developed by prolific hacker Christopher Domas, famous for finding CPU flaws like Sandsifter and God Mode Unlocked. Only AMD chips from the 15h and 16h families are affected, roughly 2011 to 2015 vintages. Family 15 is FX-series desktop chips and some Opterons, while 16h includes low-power Jaguar- and Puma-based SoCs like those in the PlayStation 4 and Xbox One, plus a handful of Athlon, Sempron, and Opteron-X chips, among others.
