CVE-2021-4090
Medium
Elevated severity or exploit probability.
CVSS base
7.1
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS — probability of exploitation (30 days)
0.3%
27.4th percentile
CISA KEV
Not listed
Weakness / dates
CWE-787
Published 2022-02-18 · modified 2026-08-25
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | N | None |
Timeline
- 2022-02-18 — Published (NVD)
- 2026-08-25 — Last modified (NVD)
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.
Affected
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2025101
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c0019b7db1d7ac62c711cda6b357a659d46428fe
- https://lore.kernel.org/linux-nfs/163692036074.16710.5678362976688977923.stgit%40klimt.1015granger.net/
- https://security.netapp.com/advisory/ntap-20220318-0010/
- 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