CVE-2021-33034
kernel: use-after-free in net/bluetooth/hci_event.c when destroying an hci_chan
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · March 22, 2021
Updated · August 14, 2026
Description
A use-after-free flaw was found in hci_send_acl in the bluetooth host controller interface (HCI) in Linux kernel, where a local attacker with an access rights could cause a denial of service problem on the system The issue results from the object hchan, freed in hci_disconn_loglink_complete_evt, yet still used in other places. The highest threat from this vulnerability is to data integrity, confidentiality and system availability.
CVSS score applicability
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.
Mitigation
Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.
CVSS / CWE
CVSS 3.1 · 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 · Use After Free