---
id: "CVE-2021-0920"
kind: "vulnerability"
aliases: ["CVE-2021-0920"]
title: "Android Kernel: Android Kernel Race Condition Vulnerability"
severity: "high"
cvss: 6.9
epss: 0.00867
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Android Kernel", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["android", "exploited", "infrastructure", "mobile-devices"]
not_affected_if: ["fully-patched-devices"]
published_at: "2021-12-15T19:15:11+00:00"
first_seen_at: "2026-10-23T19:11:52+00:00"
updated_at: "2026-10-23T21:57:35+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-0920", "first_seen_at": "2026-10-23T19:11:52+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2021-0920", "first_seen_at": "2026-10-23T19:13:45+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-0920", "first_seen_at": "2026-10-23T21:57:35+00:00"}]
---

# Android Kernel: Android Kernel Race Condition Vulnerability

The Android kernel has a race condition that leads to a use-after-free. An attacker who runs code on the device can use it to escalate privileges.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Android Kernel affected ? fixed ?

## Fix

Apply the Android security update that includes the vendor fix for CVE-2021-0920, per vendor instructions.

## Timeline

- 2026-10-23T19:11:52+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-0920
- 2026-10-23T19:13:45+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2021-0920
- 2026-10-23T21:57:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2021-0920

## From the sources

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

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_