What is CVE-2021-4202?

CVE-2021-4202 is a high-severity vulnerability in Linux Kernel, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.0/10. Published 2022-03-25.

How severe is CVE-2021-4202?

High severity. CVSS v3 base score is 7.0 out of 10.

Use After Free in Linux Kernel

CVE-2021-4202

A use-after-free flaw was found in nci_request in net/nfc/nci/core.c in NFC Controller Interface (NCI) in the Linux kernel. This flaw could allow a local attacker with user privileges to cause a data race problem while the device is getting removed, leading to a privilege escalation problem.

Vulnerability class: Race Condition

Published 2022-03-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (28.1th percentile), scored 2026-10-06.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Linux Kernel
Kernel — versions kernel 5.16 rc2

Weakness classification (CWE)

References

bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/ (Exploit, Patch, Vendor Advisory)
git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/ (Exploit, Patch, Vendor Advisory)
git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/ (Exploit, Patch, Vendor Advisory)
security.netapp.com/advisory/ntap-20220513-0002/ (Third Party Advisory)
www.openwall.com/lists/oss-security/2022/06/01/2 (mailing-list, Mailing List, Third Party Advisory)
www.openwall.com/lists/oss-security/2022/06/04/2 (mailing-list, Mailing List, Third Party Advisory)
www.openwall.com/lists/oss-security/2022/06/07/2 (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-4202?: CVE-2021-4202 is a high-severity vulnerability in Linux Kernel, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.0/10. Published 2022-03-25.
How severe is CVE-2021-4202?: High severity. CVSS v3 base score is 7.0 out of 10.