CVE-2021-28964

Name: CVE-2021-28964
Creator: NVD / NIST
Published: 2021-03-22T09:15:13.517+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.7/10EPSS 0.27%

Last modified Jun 17, 2026

CVE-2021-28964 is a medium-severity vulnerability rated 4.7/10 on the CVSS scale. A race condition was discovered in get_old_root in fs/btrfs/ctree.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (BUG) because of a lack of locking on an extent buffer before a cloning operation, aka CID-dbcc7d57bffc.. EPSS estimates a 0.27% chance of exploitation in the next 30 days.

Description

A race condition was discovered in get_old_root in fs/btrfs/ctree.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (BUG) because of a lack of locking on an extent buffer before a cloning operation, aka CID-dbcc7d57bffc.

Metrics

CVSS 3.1

4.7/10

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

EPSS Probability

0.27%

18.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-362

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	<= 5.11.8
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34
Debian	Debian Linux	9.0
Netapp	Cloud Backup	All versions
Netapp	Solidfire Baseboard Management Controller Firmware	All versions
Netapp	Aff A250 Firmware	All versions
Netapp	Fas 500f Firmware	All versions

References

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dbcc7d57bffc0c8cac9dac11bec548597d59a6a5Mailing List, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4VCKIOXCOZGXBEZMO5LGGV5MWCHO6FT3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PTRNPQTZ4GVS46SZ4OBXY5YDOGVPSTGQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T2S3I4SLRNRUQDOFYUS6IUAZMQNMPNLG/
https://security.netapp.com/advisory/ntap-20210430-0003/Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dbcc7d57bffc0c8cac9dac11bec548597d59a6a5Mailing List, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4VCKIOXCOZGXBEZMO5LGGV5MWCHO6FT3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PTRNPQTZ4GVS46SZ4OBXY5YDOGVPSTGQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T2S3I4SLRNRUQDOFYUS6IUAZMQNMPNLG/
https://security.netapp.com/advisory/ntap-20210430-0003/Third Party Advisory

Timeline

Published: Mar 22, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-28964?

How severe is CVE-2021-28964?

CVE-2021-28964 has a CVSS score of 4.7/10 (MEDIUM severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.

How do I fix CVE-2021-28964?

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-2021-28964?

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

Scan your code now

Source: NVD / NIST