A memory corruption vulnerability in HddPassword in Insyde InsydeH2O kernel 5.2 prior to 05.29.09, kernel 5.3 prior to 05.38.09, kernel 5.4 prior to 05.46.09, kernel 5.5 prior to 05.54.09, and kernel 5.6 prior to 05.61.09 could lead to escalating privileges in SMM.