CVE-2021-3564

Name: CVE-2021-3564
Creator: NVD / NIST
Published: 2021-06-08T12:15:11.753+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.48%

Last modified Jun 17, 2026

CVE-2021-3564 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. A flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious HCI TTY Bluetooth device. A local user could use this flaw to crash the system. EPSS estimates a 0.48% chance of exploitation in the next 30 days.

Description

A flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious HCI TTY Bluetooth device. A local user could use this flaw to crash the system. This flaw affects all the Linux kernel versions starting from 3.13.

Metrics

CVSS 3.1

5.5/10

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

EPSS Probability

0.48%

37.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 3.13
Fedoraproject	Fedora	34
Debian	Debian Linux	9.0

References

http://www.openwall.com/lists/oss-security/2021/05/25/1Exploit, Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/06/01/2Exploit, Mailing List
https://bugzilla.redhat.com/show_bug.cgi?id=1964139Issue Tracking, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.htmlThird Party Advisory
https://www.openwall.com/lists/oss-security/2021/05/25/1Exploit, Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/25/1Exploit, Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/06/01/2Exploit, Mailing List
https://bugzilla.redhat.com/show_bug.cgi?id=1964139Issue Tracking, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.htmlThird Party Advisory
https://www.openwall.com/lists/oss-security/2021/05/25/1Exploit, Mailing List, Third Party Advisory

Timeline

Published: Jun 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3564?

How severe is CVE-2021-3564?

CVE-2021-3564 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.48% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3564?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-3564?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST