If we consider only the devices Xiaomi, here downright a considerable army. Only in 2015, the company shipped more than 70 million gadgets with MIUI. They are vulnerable because the relevant bug for all firmwares up to version 7.2.xxxx Stable. However, in the latest firmware versions that exist for almost all devices, the vulnerability is already closed. We strongly recommend you to updated.
IBM X-Force found in the firmware MIUI, which gives us Xiaomi company, a serious vulnerability that enables the attacker to run on the user devices of arbitrary code. While MIUI installed only on devices Xiaomi, but also officially issued by the company and for devices of other vendors, and also unofficially ported craftsmen are not those devices that are not officially supported, but have an audience of users.