# CVE-2021-0920: Android Kernel Race Condition > A race condition in the Android kernel's unix socket handling allows local attackers to escalate privileges to system level. - **Severity:** Medium 6.4 (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Yes, since 23 May 2022 (CISA KEV) - **Login needed:** An administrator - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 15 Dec 2021 - **Updated:** 21 Oct 2025 - **Also known as:** A-196926917, ASB-A-196926917, DEBIAN-CVE-2021-0920, GHSA-r93f-j2vf-vmc4, SUSE-SU-2022:0647-1, SUSE-SU-2022:0667-1, SUSE-SU-2022:0996-1, UBUNTU-CVE-2021-0920 ## What is CVE-2021-0920? CVE-2021-0920 is a medium-severity use after free vulnerability in Debian Debian Linux, published on 15 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim. ### Official 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 Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), CWE-416 (Use After Free) ## Which versions are affected by CVE-2021-0920? It affects 3 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `kgraft-patch-SLE12-SP4_Update_19` | SUSE:Linux Enterprise Live Patching 12 SP4 | All versions | 15-2.2 | | `kgraft-patch-SLE12-SP4_Update_20` | SUSE:Linux Enterprise Live Patching 12 SP4 | All versions | 12-2.1 | | `kgraft-patch-SLE12-SP4_Update_21` | SUSE:Linux Enterprise Live Patching 12 SP4 | All versions | 11-2.1 | | `kgraft-patch-SLE12-SP4_Update_22` | SUSE:Linux Enterprise Live Patching 12 SP4 | All versions | 9-2.1 | | `kgraft-patch-SLE12-SP4_Update_23` | SUSE:Linux Enterprise Live Patching 12 SP4 | All versions | 4-2.1 | | `kgraft-patch-SLE12-SP5_Update_16` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 15-2.2 | | `kgraft-patch-SLE12-SP5_Update_17` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 13-2.1 | | `kgraft-patch-SLE12-SP5_Update_18` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 12-2.1 | | `kgraft-patch-SLE12-SP5_Update_19` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 10-2.1 | | `kgraft-patch-SLE12-SP5_Update_20` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 10-2.1 | | `kgraft-patch-SLE12-SP5_Update_21` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 9-2.1 | | `kgraft-patch-SLE12-SP5_Update_22` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 8-2.1 | | `kgraft-patch-SLE12-SP5_Update_23` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 6-2.1 | | `kgraft-patch-SLE12-SP5_Update_24` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 6-2.1 | | `kgraft-patch-SLE12-SP5_Update_25` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 4-2.1 | | `kgraft-patch-SLE12-SP5_Update_26` | SUSE:Linux Enterprise Live Patching 12 SP5 | All versions | 4-2.1 | | `kernel-livepatch-SLE15_Update_23` | SUSE:Linux Enterprise Live Patching 15 | All versions | 15-2.2 | | `kernel-livepatch-SLE15_Update_24` | SUSE:Linux Enterprise Live Patching 15 | All versions | 12-2.1 | | `kernel-livepatch-SLE15_Update_25` | SUSE:Linux Enterprise Live Patching 15 | All versions | 9-2.1 | | `kernel-livepatch-SLE15_Update_26` | SUSE:Linux Enterprise Live Patching 15 | All versions | 4-2.1 | | `kernel-livepatch-SLE15-SP1_Update_23` | SUSE:Linux Enterprise Live Patching 15 SP1 | All versions | 15-2.2 | | `kernel-livepatch-SLE15-SP1_Update_24` | SUSE:Linux Enterprise Live Patching 15 SP1 | All versions | 12-2.1 | | `kernel-livepatch-SLE15-SP1_Update_25` | SUSE:Linux Enterprise Live Patching 15 SP1 | All versions | 11-2.1 | | `kernel-livepatch-SLE15-SP1_Update_26` | SUSE:Linux Enterprise Live Patching 15 SP1 | All versions | 9-2.1 | | `kernel-livepatch-SLE15-SP1_Update_27` | SUSE:Linux Enterprise Live Patching 15 SP1 | All versions | 4-2.1 | | `kernel-livepatch-SLE15-SP2_Update_25` | SUSE:Linux Enterprise Live Patching 15 SP2 | All versions | 2-150200.2.1 | | `kgraft-patch-SLE12-SP3_Update_38` | SUSE:Linux Enterprise Server 12 SP3-LTSS | All versions | 15-2.2 | | `kgraft-patch-SLE12-SP3_Update_39` | SUSE:Linux Enterprise Server 12 SP3-LTSS | All versions | 12-2.1 | | `kgraft-patch-SLE12-SP3_Update_40` | SUSE:Linux Enterprise Server 12 SP3-LTSS | All versions | 9-2.1 | | `kgraft-patch-SLE12-SP3_Update_41` | SUSE:Linux Enterprise Server 12 SP3-LTSS | All versions | 5-2.1 | | `kgraft-patch-SLE12-SP3_Update_38` | SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 15-2.2 | | `kgraft-patch-SLE12-SP3_Update_39` | SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 12-2.1 | | `kgraft-patch-SLE12-SP3_Update_40` | SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 9-2.1 | | `kgraft-patch-SLE12-SP3_Update_41` | SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 5-2.1 | Products: Debian Debian Linux, Google Android, Linux kernel. ## How do I fix CVE-2021-0920? Apply the vendor's patch. US federal agencies must fix it by 13 Jun 2022. ## Is CVE-2021-0920 being exploited? Yes. Attackers have exploited CVE-2021-0920 in the wild since at least 23 May 2022. ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-0920 and fix it if it is affected. What it is: CVE-2021-0920 is a medium-severity use after free vulnerability in Debian Debian Linux, published on 15 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: Yes. Attackers have exploited CVE-2021-0920 in the wild since at least 23 May 2022. Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2021-0920/ (Markdown: https://insights.sbomify.com/CVE-2021-0920/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-0920 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-0920 - OSV: https://osv.dev/vulnerability/CVE-2021-0920 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-0920/ Summaries are generated and may contain mistakes; the official description above is the record.