An issue was discovered in Insyde InsydeH2O kernel 5.2 before version 05.29.50, kernel 5.3 before version 05.38.50, kernel 5.4 before version 05.46.50, kernel 5.5 before version 05.54.50, kernel 5.6 before version 05.61.50, and kernel 5.7 before version 05.70.50. In VariableRuntimeDxe driver, SecureBootHandler uses DataSize and VariableNameSize when determining if the data or name are in the buffer, but these are supplied by the caller and therefore cannot be trusted.