An issue was discovered in Insyde InsydeH2O with kernel 5.0 through 5.5. A stack buffer overflow leads to arbitrary code execution in the SetupUtility driver on Intel platforms. An attacker can change the values of certain UEFI variables. If the size of the second variable exceeds the size of the first, then the buffer will be overwritten. This issue affects the SetupUtility driver of InsydeH2O.