New DRAM Scrambling Attack Compromises AMD CPU Security Features

Security researcher Christopher Domas has unveiled a new attack technique called 'skitter-creek-bath-salts' that exploits vulnerabilities in AMD Family 15h and 16h processors. This attack manipulates the memory controller to disable address scrambling, allowing unauthorized access to critical areas such as the Platform Security Processor (PSP), System Management Mode (SMM), and microcode storage. The proof-of-concept project demonstrates how an attacker with kernel-level access can read and modify protected firmware memory. AMD has stated that the affected processors are no longer under regular security support. This vulnerability poses a significant risk to systems still using these older AMD CPUs, as it bypasses hardware-enforced memory isolation. The attack highlights the ongoing challenges in securing legacy hardware against modern threats.

Key Points: • The 'skitter-creek-bath-salts' attack targets AMD Family 15h and 16h processors. • It disables memory-address scrambling, exposing critical security features. • Affected processors are no longer under regular security support from AMD.