Introduction A buffer overflow is “one of the most important exploitation techniques in the history of computer security.” [ Tanenbaum]^[1] “Buffer overflows are ideally suited for introducing three of the most important protection mechanisms available in most modern systems: stack canaries, data execution protection, and address-space layout randomization.” [Tanenbaum] ^[1] However, the current UEFI firmware implementation only adopted a few of these mechanisms. This paper will introduce how to enable the protection mechanisms in UEFI firmware to harden the pre-boot phase.