OpenHarmony-v3.1.2 and prior versions, 3.0.6 and prior versions have a Kernel memory pool override vulnerability in /dev/mmz_userdev device driver. The impact depends on the privileges of the attacker. The unprivileged process run on the device could disclose sensitive information including kernel pointer, which could be used in further attacks. The processes with system user UID run on the device would be able to mmap memory pools used by kernel and override them which could be used to gain kernel code execution on the device, gain root privileges, or cause device reboot.