In this guide, we will break down what “critical init step 3” actually means, why it fails, and what you can do about it.
The most common devices to encounter the "Failed critical init step 3" error are Amazon Fire tablets, particularly the HD 8 and HD 10 models. Users report that even when following the correct steps—pushing mtk-su to /data/local/tmp/ , setting permissions with chmod 755 , and running the binary—they are greeted with the error message". Some users have noted that only the first few months of Fire OS builds contained the exploit; later ROM versions had it blocked, and many tablets now have the vulnerability patched by default.
Some devices, like the ZTE Blade A7 Prime, have the fastboot oem unlock commands removed entirely, making permanent rooting impossible regardless of mtk-su’s status. In such cases, even if mtk-su worked, you might still be limited to temporary root only. mtk-su failed critical init step 3
Google and MediaTek frequently update the kernel to patch security vulnerabilities. If your device runs a recent Android security patch (usually from late 2020 onward, though it varies by device), the vulnerability used by mtk-su has likely been patched. 2. Android Version Incompatibility
– just that this specific exploit won’t work. For newer devices, unlock the bootloader (if allowed by the manufacturer) and use Magisk. For locked bootloaders on patched kernels, temp root via mtk-su is no longer possible. In this guide, we will break down what
Fix permissions and context
Find a factory firmware file for your specific device model dated . Some users have noted that only the first
The CVE-2020-0069 vulnerability was officially patched by Google and MediaTek in . If your device has a security patch level from March 2020 or later, the firmware contains code that blocks mtk-su from executing its memory override. 2. Incompatible Kernel Configuration