CVE-2021-4159

Name: CVE-2021-4159
Creator: NVD / NIST
Published: 2022-08-24T16:15:09.713+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.4/10EPSS 0.24%

Last modified Jun 17, 2026

CVE-2021-4159 is a medium-severity vulnerability rated 4.4/10 on the CVSS scale. A vulnerability was found in the Linux kernel's EBPF verifier when handling internal data structures. Internal memory locations could be returned to userspace. EPSS estimates a 0.24% chance of exploitation in the next 30 days.

Description

A vulnerability was found in the Linux kernel's EBPF verifier when handling internal data structures. Internal memory locations could be returned to userspace. A local attacker with the permissions to insert eBPF code to the kernel can use this to leak internal kernel memory details defeating some of the exploit mitigations in place for the kernel.

Metrics

CVSS 3.1

4.4/10

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

0.24%

14.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-202

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	< 5.7
Redhat	Enterprise Linux	8.0
Debian	Debian Linux	10.0

References

https://access.redhat.com/security/cve/CVE-2021-4159Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2036024Issue Tracking
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=294f2fc6da27620a506e6c050241655459ccd6bdMailing List, Patch, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2022/10/msg00000.htmlMailing List, Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2021-4159Third Party Advisory
https://access.redhat.com/security/cve/CVE-2021-4159Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2036024Issue Tracking
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=294f2fc6da27620a506e6c050241655459ccd6bdMailing List, Patch, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2022/10/msg00000.htmlMailing List, Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2021-4159Third Party Advisory

Timeline

Published: Aug 24, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-4159?

How severe is CVE-2021-4159?

CVE-2021-4159 has a CVSS score of 4.4/10 (MEDIUM severity). The EPSS model estimates a 0.24% probability of exploitation in the next 30 days.

How do I fix CVE-2021-4159?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-4159?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST