CVE-2021-0920

Use After Free

CVSS 3.1 Medium 6.4Known exploited (CISA KEV)

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

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

Key data

CVSS 3.1 Medium 6.4

Score published by CISA-ADP in the CVE record.

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

Attack vector: Local
The attacker needs local access to the system, or to trick a user into running something.
Attack complexity: High
The attack depends on conditions outside the attacker's control, so it takes preparation.
Privileges required: High
An account with significant privileges, such as an administrator, is needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: High
Serious or total effect on the secrecy of data.
Integrity impact: High
Serious or total effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.

Metric	Value	What it means
Attack vector	Local	The attacker needs local access to the system, or to trick a user into running something.
Attack complexity	High	The attack depends on conditions outside the attacker's control, so it takes preparation.
Privileges required	High	An account with significant privileges, such as an administrator, is needed.
User interaction	None	No action from any user is needed.
Scope	Unchanged	The impact stays within the vulnerable component.
Confidentiality impact	High	Serious or total effect on the secrecy of data.
Integrity impact	High	Serious or total effect on the trustworthiness of data.
Availability impact	High	Serious or total effect on availability.

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at first.org/cvss.

EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score: 0.00867 (0.9% probability)
Percentile: 59.0%
Scores of: Nov 10, 2026
Model: v2026.06.15

CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog: Android Kernel Race Condition Vulnerability
Added to the catalog: May 23, 2022
Federal due date: Jun 13, 2022

CISA assessment as of Feb 6, 2024

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation: Recorded by CISA as active
Automatable: no
Technical impact: total

Weakness (CWE)

CWE catalog version 5.0.

CWE-416Use After Free

Affected products

Products listed in the CVE record, as the CNA published them.

Android
- affected: Android kernel

References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

source.android.com/security/bulletin/2021-11-01
[debian-lts-announce] 20211216 [SECURITY] [DLA 2843-1] linux security update (lists.debian.org)mailing-list

Timeline

ID reservedNov 6, 2020
Record publishedDec 15, 2021
Added to CISA KEVMay 23, 2022
Record last updatedOct 21, 2025

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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:29 UTC. Sources and licenses