HUAWEI Mate 30 with versions earlier than 10.1.0.150(C00E136R5P3) have a type confusion vulnerability. The system does not properly check and transform the type of certain variable, the attacker tricks the user into installing then running a crafted application, successful exploit could cause code execution.
https://www.huawei.com/en/psirt/security-advisories/huawei-sa-20200701-05-smartphone-en