CVE-2021-0920

Name: CVE-2021-0920
Creator: NVD / NIST
Published: 2021-12-15T19:15:11.017+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.4/10Actively ExploitedEPSS 0.81%

Last modified Jun 17, 2026

CVE-2021-0920 is a medium-severity vulnerability rated 6.4/10 on the CVSS scale. In unix_scm_to_skb of af_unix.c, there is a possible use after free bug due to a race condition. This could lead to local escalation of privilege with System execution privileges needed. CISA has confirmed active exploitation in the wild. EPSS estimates a 0.81% chance of exploitation in the next 30 days.

Description

In unix_scm_to_skb of af_unix.c, there is a possible use after free bug due to a race condition. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-196926917References: Upstream kernel

Metrics

CVSS 3.1

6.4/10

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

EPSS Probability

0.81%

52.3th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Jun 13, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	<= 5.13	—
Linux	Linux Kernel	5.14	Rc1
Google	Android	All versions	—
Debian	Debian Linux	9.0	—

References

https://lists.debian.org/debian-lts-announce/2021/12/msg00012.htmlMailing List, Third Party Advisory
https://source.android.com/security/bulletin/2021-11-01Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/12/msg00012.htmlMailing List, Third Party Advisory
https://source.android.com/security/bulletin/2021-11-01Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-0920Third Party Advisory, US Government Resource

Timeline

Published: Dec 15, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-0920?

How severe is CVE-2021-0920?

CVE-2021-0920 has a CVSS score of 6.4/10 (MEDIUM severity). The EPSS model estimates a 0.81% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-0920?

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-2021-0920?

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

Scan your code now

Source: NVD / NIST