Use-After-Free Vulnerability in Linux Kernel HCI Subsystem

CVE-2021-3573 · MEDIUM Severity

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

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.

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