CVE-2022-20166

What it actually does

Heap buffer overflow in kernel base drivers enabling out-of-bounds write that can be leveraged for local privilege escalation when an attacker already possesses System execution privileges.

Why it matters to the business

Devices running the affected kernel could be fully compromised by a local attacker who already has elevated access, increasing the risk of data theft, persistence, or further lateral movement within an organization fleet.

How an attack unfolds

An attacker with existing System-level access on an Android device crafts input that triggers the vulnerable kernel driver paths, overflows a heap buffer, and overwrites adjacent memory structures to elevate privileges beyond the System account.

How to fix it

Update the Android kernel to a version containing the upstream fix referenced by Android ID A-182388481. For the usememos/memos component, apply the commit 3556ae4e651d9443dc3bb8a170dd3cc726517a53 or later.

How to confirm the fix worked

Confirm the kernel build contains the referenced upstream patch and that the vulnerable driver methods no longer accept inputs capable of overflowing the heap buffer; re-test privilege-escalation paths with System credentials.

Typical attack path

1. Obtain System execution privileges on the target device through a separate vector
2. Invoke one of the affected kernel base driver methods with malicious parameters
3. Trigger the heap buffer overflow to perform an out-of-bounds write
4. Overwrite kernel data structures to gain higher privileges such as root or kernel code execution

How to detect it

Examine kernel logs and audit records for unexpected calls to the affected base driver methods followed by abnormal memory allocation patterns or privilege changes; correlate with any post-exploitation activity such as new root processes.

What your security team should do

• Prioritize kernel updates on all Android devices as soon as vendor patches are available
• Review device inventory for any remaining unpatched kernels given the 1586 days since disclosure
• Limit the number of accounts or processes that can obtain System privileges to reduce the attack surface
• Monitor for any new exploit maturity indicators or EPSS increases