Vulnerability in Linux Kernel
CVE-2021-3573
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.
Vulnerability class: Race Condition
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (28.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Linux Kernel — versions 5.13
- Fedoraproject Fedora — versions 34
- Red Hat Enterprise Linux — versions 6.0, 7.0, 8.0
- Kernel — versions kernel 5.13-rc5
Weakness classification (CWE)
Public proof-of-concept exploits
- ARPSyndicate/cvemon
- hardenedvault/ved
- kdn111/linux-kernel-exploitation
- khanhdn111/linux-kernel-exploitation
- khanhdz-06/linux-kernel-exploitation
- khanhdz191/linux-kernel-exploitation
- khanhhdz/linux-kernel-exploitation
- khanhhdz06/linux-kernel-exploitation
- khanhnd123/linux-kernel-exploitation
- khnhdz/linux-kernel-exploitation
References
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git/commit/ (Patch, Vendor Advisory)
- www.openwall.com/lists/oss-security/2021/06/08/2 (Exploit, Mailing List, Third Party Advisory)
- www.openwall.com/lists/oss-security/2023/07/02/1 (mailing-list)
Frequently asked questions
- What is CVE-2021-3573?
- CVE-2021-3573 is a medium-severity vulnerability in Linux Kernel, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 6.4/10. Published 2021-08-13.
- How severe is CVE-2021-3573?
- Medium severity. CVSS v3 base score is 6.4 out of 10.
- Is CVE-2021-3573 known to be exploited?
- 16 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.