CVE-2021-3573

CVE-2021-3573 is a use-after-free vulnerability in the Linux kernel's HCI subsystem, affecting versions prior to 5.13-rc5, including various Fedora and Red Hat Enterprise Linux distributions. A privileged local user can exploit this flaw by triggering a race condition during HCI device unregistration and other HCI socket operations. This vulnerability carries a CVSS score of 6.4 (Medium), indicating that an attacker with high privileges and high attack complexity could achieve high impact on confidentiality, integrity, and availability, potentially leading to system crashes or privilege escalation. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion surrounding this CVE.