CVE-2021-4090
Description
An out-of-bounds (OOB) memory write flaw was found in the NFSD in the Linux kernel. Missing sanity may lead to a write beyond bmval[bmlen-1] in nfsd4_decode_bitmap4 in fs/nfsd/nfs4xdr.c. In this flaw, a local attacker with user privilege may gain access to out-of-bounds memory, leading to a system integrity and confidentiality threat.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Linux kernel Affected 2 releases
| Version | Status | Fixed in |
|---|---|---|
| 5.16 | Affected | — |
| — | Affected | 5.16 |
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 5.15.5-1 |
| sid | Fixed | 5.15.5-1 |
| forky | Fixed | 5.15.5-1 |
| bullseye | Fixed | 0 |
| bookworm | Fixed | 5.15.5-1 |
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2025101
- https://lore.kernel.org/linux-nfs/163692036074.16710.5678362976688977923.stgit%40klimt.1015granger.net/
- https://security.netapp.com/advisory/ntap-20220318-0010/
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://www.suse.com/security/cve/CVE-2021-4090.html
- https://security-tracker.debian.org/tracker/CVE-2021-4090
CWEs
CWE-787
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.