OpenHarmony-v3.1.2 and prior versions, 3.0.6 and prior versions have an Out-of-bound memory read and write vulnerability in /dev/mmz_userdev device driver. The impact depends on the privileges of the attacker. The unprivileged process run on the device could read out-of-bound memory leading sensitive to information disclosure. The processes with system user UID run on the device would be able to write out-of-bound memory which could lead to unspecified memory corruption.