High · published July 11, 2025
A vulnerability in the Software SMI handler (SwSmiInputValue 0xB2) allows a local attacker to control the RBX register, which is used as an unchecked pointer in the CommandRcx0 function. If the contents at RBX match certain expected values (e.g., '$DB$' or '2DB$'), the function performs arbitrary writes to System Management RAM (SMRAM), leading to potential privilege escalation to System Management Mode (SMM) and persistent firmware compromise.