CVE-2024-50255
Description
A flaw was found in the Linux kernel's Bluetooth Host Controller Interface (HCI) component. A null pointer dereference occurs in the hci_read_supported_codecs function because __hci_cmd_sync_sk() incorrectly returns a NULL value for unknown opcodes. A local attacker with low privileges could exploit this vulnerability to trigger a system crash, resulting in a Denial of Service (DoS).
Mitigation
To mitigate this vulnerability, disable the Bluetooth kernel module if Bluetooth functionality is not required. This can be achieved by blacklisting the `bluetooth` module.
1. Create a file `/etc/modprobe.d/disable-bluetooth.conf` with the following content:
blacklist bluetooth2. Regenerate the initramfs:
install bluetooth /bin/true
bashor for systems using `mkinitrd`:
sudo dracut -f -v
bash3. Reboot the system for the changes to take effect.
sudo mkinitrd -f /boot/initramfs-$(uname -r).img $(uname -r)
This mitigation will prevent the `bluetooth` module from loading, effectively disabling Bluetooth functionality. A system reboot is required for the changes to be applied.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 5.5 | 5.5 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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