> CVE-2022-21766: Mediatek CCCI Kernel Driver Stack Buffer Overflow

We have identified a new stack buffer overflow vulnerability in Mediatek’s Linux Kernel driver implementation of cellular-to-application processor communication interface (CCCI). The vulnerability can be exploited by a malicious (compromised) baseband runtime to achieve arbitrary code execution in the Linux Kernel. The vulnerability we are disclosing in this advisory affected a wide range of Mediatek devices, including phones on the newest chipsets (Dimensity 700, 1000, etc). The July 2022 issue of the Mediatek Security Bulletin contains this vulnerability as CVE-2022-21766. Vulnerability Details There is a kernel stack buffer overflow vulnerability in the implementation of the modem-kernel communication interface. The stack overflow can be used to overwrite the return address of a kernel function, with attacker controlled data.