CVE-2021-3573 Use after free in kernel

What is CVE-2021-3573?

CVE-2021-3573 is a medium-severity use after free vulnerability in Fedoraproject Fedora, published on 13 Aug 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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.

Weakness: CWE-362

Which versions are affected by CVE-2021-3573?

It affects 3 products.

Products include Fedoraproject Fedora, Linux kernel, Redhat Enterprise Linux.

How do I fix CVE-2021-3573?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2021-3573 being exploited?

There is no known exploitation of CVE-2021-3573 in the wild and no public exploit code.

Other vulnerabilities in Fedoraproject Fedora

• CVE-2024-4577 PHP-CGI OS Command Injection Exploited Critical 9.8
• CVE-2021-39226 Grafana Authentication Bypass Exploited Critical 9.8
• CVE-2019-5544 VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Exploited Critical 9.8
• CVE-2024-4947 Google Chromium V8 Type Confusion Exploited Critical 9.6
• CVE-2024-4671 Google Chromium Visuals Use-After-Free Exploited Critical 9.6

All Fedoraproject Fedora vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-6574, DEBIAN-CVE-2021-3573, GHSA-73pg-2qfc-2cfm, UBUNTU-CVE-2021-3573.