October 26, 2023 Author: The Embedded Reverser Introduction: The Cat and Mouse Game If you have ever tried to flash a MediaTek (MTK) device using SP Flash Tool, you have likely encountered the dreaded STATUS_SEC_AUTH_FILE_NEEDED or S_DL_GET_DRAM_SETTING_FAIL error. This is the "Secured Boot" wall. For years, MTK devices shipped with a known vulnerability (often referred to as the "Auth Bypass" or "SLA/DAA" bypass) that allowed technicians and developers to flash preloader and bootloader images without authorized authentication.

The source code (often released on GitHub under mtkclient forks) reveals that Rev 4 exploits a stack buffer overflow in the BROM's string parser for the USB_DL_STRING descriptor. It is a beautiful piece of exploitation. Final Thoughts MediaTek has patched this vulnerability in their latest silicon (MT6985 and newer), but the sheer volume of existing devices means Rev 4 will remain relevant for at least another 3 years .

, which may involve glitching the power rail to bypass the new eFuse protections. Have you successfully used Rev 4 on a Dimensity 8200? Let us know in the comments below.

Here is everything you need to know about Rev 4, how it works, and how to use it safely. Before Rev 4, we relied on the "SLA/DAA" (Serial Link Authentication / Device Authentication Algorithm) weakness found in MTK's BootROM. The BootROM is the first code that runs on your phone. If we can crash it or fool it into thinking we are a legitimate bootloader, we can force the CPU to accept unsigned code.