MEDIUM
CVE-2021-28964
CWE-362Published: March 22, 2021· Updated: Jun 17, 2026
4.7
CVSS v3.1
Official 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.
Technical Analysis
CVE-2021-28964 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 4.7.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorLocal
Attack ComplexityHigh
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected Vendors & Products
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
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Official Patches & Advisories
All References (14)
→
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://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://security.netapp.com/advisory/ntap-20210430-0003/Third Party Advisory
Quick Facts
CVE IDCVE-2021-28964
CVSS Score4.7 / 10
SeverityMEDIUM
WeaknessCWE-362
CISA KEVNo
Affected4 vendor(s)
PublishedMar 22, 2021
Related CVEs (CWE-362)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-28964 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.