CVE-2023-54214

Vulnerability

Overview

CVE-2023-54214 is a use-after-free vulnerability in the Linux kernel's Bluetooth L2CAP implementation. The root cause lies in the [1] is that certain code paths call alloc_skb to allocate a buffer, which may temporarily release the channel lock and reacquire it later. During this window, the channel can be disconnected, leading to a use-after-free condition when the code subsequently accesses the freed channel structure.

Exploitation

An attacker with the ability to trigger Bluetooth L2CAP operations on a vulnerable system can exploit this race condition. The attack requires the ability to initiate or influence L2CAP channel operations, potentially from a local unprivileged process or a nearby Bluetooth device. The vulnerability is triggered when a buffer allocation coincides with a channel disconnection, causing the code to operate on freed memory.

Impact

Successful exploitation could lead to memory corruption, system crash (denial of service), or potentially arbitrary code execution in the kernel context. The impact is limited to systems with the affected Linux kernel versions that have the Bluetooth L2CAP subsystem enabled.

Mitigation

The fix is included in stable kernel updates [1][2][3][4]. Users should apply the latest kernel updates from their distribution. No workaround is available other than disabling Bluetooth if not needed.