CVE-2021-3573: Fedoraproject Fedora

Medium severity, CVSS 6.4. EPSS: 0.4% chance of exploitation in the next 30 days.

A use-after-free in function hci_sock_bound_ioctl() of the Linux kernel HCI subsystem was found in the way user calls ioct HCIUNBLOCKADDR or other way triggers race condition of the call hci_unregister_dev() together with one of the calls hci_sock_blacklist_add(), hci_sock_blacklist_del(), hci_get_conn_info(), hci_get_auth_info(). A privileged local user could use this flaw to crash the system or escalate their privileges on the system. This flaw affects the Linux kernel versions prior to 5.13-rc5.

Affected products

• Fedoraproject Fedora: version 34 only
• Linux Linux Kernel: before 5.13 (fixed in 5.13); version 5.13 only
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only; version 8.0 only

Published 2021-08-13. Last modified 2026-06-17.