CVE-2021-4090

What it is

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.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2022-02-18 18:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-14 11:16 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 7.1 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2022-02-18 18:15 UTC

Last modified

2026-10-14 11:16 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-787 · Out-of-bounds write

Record status

Modified

Affected

• Linux Kernel < 5.16
• Linux Kernel 5.16
• Netapp h300s Firmware
• Netapp h500s Firmware
• Netapp h700s Firmware
• Netapp h300e Firmware
• Netapp h500e Firmware
• Netapp h700e Firmware

Attack profile CVSS 3.1 · 7.1

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-4090.md and follow it. Check whether this project is affected by CVE-2021-4090. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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