What is CVE-2021-4002?

CVE-2021-4002 is a medium-severity vulnerability in Linux Kernel, classified under Incomplete Cleanup. CVSS score: 4.4/10. Published 2022-03-03.

How severe is CVE-2021-4002?

Medium severity. CVSS v3 base score is 4.4 out of 10.

Vulnerability in Linux Kernel

CVE-2021-4002

A memory leak flaw in the Linux kernel's hugetlbfs memory usage was found in the way the user maps some regions of memory twice using shmget() which are aligned to PUD alignment with the fault of some of the memory pages. A local user could use this flaw to get unauthorized access to some data.

Published 2022-03-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.005 (41.7th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Linux Kernel — versions 5.16
Oracle Communications Cloud Native Core Binding Support Function — versions 22.1.3
Oracle Communications Cloud Native Core Network Exposure Function — versions 22.1.1
Oracle Communications Cloud Native Core Policy — versions 22.2.0
Debian Linux — versions 9.0, 10.0
Fedoraproject Fedora — versions 35
Kernel — versions affects kernel v3.6 and later through v5.15.5.

Weakness classification (CWE)

References

bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
www.openwall.com/lists/oss-security/2021/11/25/1 (Exploit, Mailing List, Third Party Advisory)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/ (Patch, Vendor Advisory)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/ (Patch, Vendor Advisory)
lists.debian.org/debian-lts-announce/2022/03/msg00011.html (mailing-list, Mailing List, Third Party Advisory)
lists.debian.org/debian-lts-announce/2022/03/msg00012.html (mailing-list, Mailing List, Third Party Advisory)
www.debian.org/security/2022/dsa-5096 (vendor-advisory, Third Party Advisory)
www.oracle.com/security-alerts/cpujul2022.html (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-4002?: CVE-2021-4002 is a medium-severity vulnerability in Linux Kernel, classified under Incomplete Cleanup. CVSS score: 4.4/10. Published 2022-03-03.
How severe is CVE-2021-4002?: Medium severity. CVSS v3 base score is 4.4 out of 10.