MediaTek MT65xx MT66xx MT8163 eMMC Subsystem - OS Command Injection via Filename in Meta Mode Boot
The MediaTek Embedded Multimedia Card (eMMC) subsystem for Android on MT65xx, MT66xx, and MT8163 SoC devices allows attackers to execute arbitrary commands as root via shell metacharacters in a filename under /data, because clear_emmc_nomedia_entry in platform/mt6577/external/meta/emmc/meta_clr_emmc.c invokes 'system("/system/bin/rm -r /data/' followed by this filename upon an eMMC clearance from a Meta Mode boot. NOTE: compromise of Fire OS on the Amazon Echo Dot would require a second hypothetical vulnerability that allows creation of the required file under /data.