What’s Vulnerable › Vulnerabilities
CVE-2021-4090
- Severity: high (CVSS 7.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2022-02-18 · updated 2026-10-14
- Weakness: CWE-787
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 products
- Linux kernel: before 5.16; 5.16, 5.16-rc1 — fixed in 5.16
- NetApp H300E Firmware: all versions
- NetApp H300S Firmware: all versions
- NetApp H410C Firmware: all versions
- NetApp H410S Firmware: all versions
- NetApp H500E Firmware: all versions
- NetApp H500S Firmware: all versions
- NetApp H700E Firmware: all versions
- NetApp H700S Firmware: all versions
How to fix
Upgrade to a fixed version: Linux kernel 5.16. Check the vendor advisory for mitigations.
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
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