According to Check Point Research, there was a security vulnerability found which was later fixed by MediaTek in October. This has let the hackers to perform various escalation attacks. The problem was related to AI and in audio processing plus an app with the right code could have access to the system level audio information which normally an app does not have. There are more sophisticated apps that could have launched sniffing attack that would have allowed the hacker to delete, change or intercept the data that was transmitted between two devices.
It was further explained by Check Point Research that this vulnerability is very complex and needed a whole team of researchers to reverse engineer the process. The app could have passed a command to an audio interface to extract the information only if the attacker knew about the MediaTek firmware exploits. There is still no information that such attack has taken place and the current owners of the devices housing MediaTek chipsets should not have to worry as the company has patched vulnerability in October update.