An issue was discovered in NvmExpressDxe in Insyde InsydeH2O with kernel 5.1 through 5.5. An SMM memory corruption vulnerability allows an attacker to write fixed or predictable data to SMRAM. Exploiting this issue could lead to escalating privileges to SMM.
An issue was discovered in AtaLegacySmm in the kernel 5.0 before 05.08.46, 5.1 before 05.16.46, 5.2 before 05.26.46, 5.3 before 05.35.46, 5.4 before 05.43.46, and 5.5 before 05.51.45 in Insyde InsydeH2O. Code execution can occur because the SMI handler lacks a CommBuffer check.