{"id":"CVE-2021-0920","kind":"vulnerability","aliases":["CVE-2021-0920"],"related":[],"title":"Android Kernel: Android Kernel Race Condition Vulnerability","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","summary":"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.","severity":"high","cvss":6.9,"epss":0.00867,"exploited":true,"exploited_at":"2022-05-23T00:00:00+00:00","products":[{"name":"Android Kernel","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["android","exploited","infrastructure","mobile-devices"],"not_affected_if":["fully-patched-devices"],"how_to_check":null,"fix":"Apply the Android security update that includes the vendor fix for CVE-2021-0920, per vendor instructions.","status":"open","published_at":"2021-12-15T19:15:11+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:16:02+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:16:02Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Android security update that includes the vendor fix for CVE-2021-0920, per vendor instructions.","reach":"local","impact":"high","summary":"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.","category":"infrastructure","who_cares":["android","mobile-devices"],"confidence":0.6,"needs_auth":"yes","worst_case":"Attacker with local code execution gains kernel-level privileges on the device.","analyst_note":"Find the affected Android security bulletin and patch level for CVE-2021-0920 and confirm the affected kernel versions; the sources give no product or version detail.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["fully-patched-devices"],"user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000439,"input_tokens":2813,"output_tokens":316,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-0920':10A,13A '-2021':9A,12A '196926917references':98C 'a-196926917references':96C 'af':57C 'android':1A,3A,14A,16B,23B,93C 'androidvers':92C 'attack':38B 'bug':66C 'code':41B 'condit':6A,28B,71C 'could':73C 'cve':8A,11A 'devic':21B,44B 'due':67C 'escal':49B,77C 'execut':82C 'exploit':17B 'exploitation.product':91C 'free':36B,65C 'id':95C 'infrastructur':18B 'interact':86C 'kernel':2A,4A,15A,24B,100C 'kernelandroid':94C 'lead':30B,74C 'local':76C 'mobil':20B 'mobile-devic':19B 'need':84C,89C 'possibl':62C 'privileg':50B,79C,83C 'race':5A,27B,70C 'run':40B 'scm':53C 'skb':55C 'system':81C 'unix':52C 'unix.c':58C 'upstream':99C 'use':34B,46B,63C 'use-after-fre':33B 'user':85C 'vulner':7A","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-12-15T19:15:11+00:00","kev":{"dateAdded":"2022-05-23","dueDate":"2022-06-13","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2021-0920","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-0920","severity":null,"published_at":"2022-05-23T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T20:35:36+00:00","note":null},{"source":"epss","external_id":"CVE-2021-0920","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-0920","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:45+00:00","fetched_at":"2026-10-23T19:13:45+00:00","note":null},{"source":"nvd","external_id":"CVE-2021-0920","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-0920","severity":null,"published_at":"2021-12-15T19:15:11+00:00","modified_at":"2026-06-17T03:30:39+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}