An issue was discovered in AhciBusDxe in the kernel 5.0 through 5.5 in Insyde InsydeH2O. Because of an Untrusted Pointer Dereference that causes SMM memory corruption, an attacker may be able to write fixed or predictable data to SMRAM. Exploiting this issue could lead to escalating privileges to SMM.

An unsafe pointer vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler. An attacker can use this unsafe pointer "current_ptr" to read or write or manipulate data into SMRAM. Exploitation of this vulnerability can lead to escalation of privileges reserved only for SMM using the SwSMI handler.