CVE-2023-53305

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: Fix use-after-free

Fix potential use-after-free in l2cap_le_command_rej.

This L2CAP issue is adjacency-only (Bluetooth LE): an attacker must be within radio range and craft malicious LE frames. Impact is primarily kernel crash / DoS. It could trigger a use-after-free condition when processing LE command rejection. In practice an attacker must either establish a BLE connection or rely on the device accepting unauthenticated L2CAP traffic. If the device enforces pairing/authentication for L2CAP operations, exploitation from an unauthenticated remote actor is unlikely. Fixed in Red Hat Enterprise Linux 9 starting from 9.4.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate these vulnerabilities on the operating system level, disable the Bluetooth functionality via blocklisting kernel modules in the Linux kernel. The kernel modules can be prevented from being loaded by using system-wide modprobe rules. Instructions on how to disable Bluetooth modules are available on the customer portal at https://access.redhat.com/solutions/2682931.

Alternatively, bluetooth can be disabled within the hardware or at the BIOS level, which will also provide effective mitigation as the kernel will not detect Bluetooth hardware on the system.