MEDIUM
CVE-2021-38199
NVD-CWE-noinfoPublished: August 8, 2021· Updated: Jun 17, 2026
6.5
CVSS v3.1
Official Description
fs/nfs/nfs4client.c in the Linux kernel before 5.13.4 has incorrect connection-setup ordering, which allows operators of remote NFSv4 servers to cause a denial of service (hanging of mounts) by arranging for those servers to be unreachable during trunking detection.
Technical Analysis
CVE-2021-38199 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 6.5.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorAdjacent
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:A/AC:L/PR:N/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
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (12)
→
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4Mailing List · Patch · Vendor Advisory
→
https://github.com/torvalds/linux/commit/dd99e9f98fbf423ff6d365b37a98e8879170f17cPatch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2021/10/msg00010.htmlMailing List · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2021/12/msg00012.htmlMailing List · Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20210902-0010/Third Party Advisory
→
https://www.debian.org/security/2021/dsa-4978Third Party Advisory
→
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4Mailing List · Patch · Vendor Advisory
→
https://github.com/torvalds/linux/commit/dd99e9f98fbf423ff6d365b37a98e8879170f17cPatch · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2021/10/msg00010.htmlMailing List · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2021/12/msg00012.htmlMailing List · Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20210902-0010/Third Party Advisory
→
https://www.debian.org/security/2021/dsa-4978Third Party Advisory
Quick Facts
CVE IDCVE-2021-38199
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected3 vendor(s)
PublishedAug 8, 2021
Related CVEs (NVD-CWE-noinfo)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-38199 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.