CVE-2021-0679

Vulnerability

In the apusys driver of MediaTek chipsets, a missing bounds check can lead to memory corruption. The vulnerability affects devices using affected chipsets (including MT6570, MT6580, MT6735, MT6737, MT6739, MT6750, MT6750S, MT6753, MT6755, MT6755S, MT6757, MT6757C, MT6757CD, MT6757CH, MT6758, MT6761, MT6763, MT6765, MT6768, MT6771, MT6779, MT6781, MT6785, MT6797, MT6799, MT6833, and others) as per the October 2021 security bulletin [1]. The vulnerability is classified as CVE-2021-0679 with a Medium severity [1].

Exploitation

An attacker requires System execution privileges to trigger the vulnerability. User interaction is not needed [1]. The exact exploitation steps are not detailed in the public reference, but the missing bounds check in the apusys memory subsystem can be leveraged to corrupt memory [1].

Impact

Successful exploitation could lead to memory corruption, potentially enabling local escalation of privilege within the kernel context [1]. The attacker can gain elevated privileges on the targeted device.

Mitigation

MediaTek has released a security patch (Patch ID: ALPS05672107) for this issue [1]. Device OEMs have been notified and are expected to deploy the fix. Users should apply security updates from their device manufacturer when available. The patch is included in the December 2021 MediaTek security bulletin [1].