{"id":"CVE-2022-24521","kind":"vulnerability","aliases":["CVE-2022-24521"],"related":[],"title":"Microsoft Windows: Microsoft Windows CLFS Driver Privilege Escalation Vulnerability","description":"Microsoft Windows Common Log File System (CLFS) Driver contains an unspecified vulnerability that allows for privilege escalation.\n\nCISA required action: Apply updates per vendor instructions.","summary":"Microsoft Windows Common Log File System (CLFS) driver has a privilege escalation flaw that lets a local user gain higher privileges. It is listed in CISA's known-exploited catalog and is tagged as used in ransomware campaigns.","severity":"high","cvss":7.8,"epss":0.07134,"exploited":true,"exploited_at":"2022-04-13T00:00:00+00:00","products":[{"name":"Microsoft Windows","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","infrastructure","ransomware","self-hosted","windows"],"not_affected_if":["patched-windows"],"how_to_check":"Check the installed Windows build and whether the April 2022 cumulative update (or later) is applied, using winver or Get-HotFix in PowerShell; the sources do not give the exact KB number.","fix":"Apply the Microsoft security update for CVE-2022-24521 per vendor instructions; the sources do not name the specific patch or fixed build.","status":"open","published_at":"2022-04-13T00:00:00+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:17:59+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:17:59Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Microsoft security update for CVE-2022-24521 per vendor instructions; the sources do not name the specific patch or fixed build.","reach":"local","impact":"high","summary":"Microsoft Windows Common Log File System (CLFS) driver has a privilege escalation flaw that lets a local user gain higher privileges. It is listed in CISA's known-exploited catalog and is tagged as used in ransomware campaigns.","category":"infrastructure","who_cares":["windows","self-hosted"],"confidence":0.6,"needs_auth":"yes","worst_case":"local attacker gains SYSTEM privileges on the Windows machine","analyst_note":"Confirm the fixed Windows builds and KB numbers from Microsoft's advisory for CVE-2022-24521 (msrc.microsoft.com); sources only say 'apply updates'.","how_to_check":"Check the installed Windows build and whether the April 2022 cumulative update (or later) is applied, using winver or Get-HotFix in PowerShell; the sources do not give the exact KB number.\nunknown","needs_analyst":true,"not_affected_if":["patched-windows"],"user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.0005,"input_tokens":2836,"output_tokens":433,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2022':11A,14A '-24521':12A,15A 'action':83C 'allow':77C 'appli':84C 'campaign':63B 'catalog':55B 'cisa':50B,81C 'clfs':5A,31B,70C 'common':27B,66C 'contain':72C 'cve':10A,13A 'driver':6A,32B,71C 'escal':8A,36B,80C 'exploit':18B,54B 'file':29B,68C 'flaw':37B 'gain':43B 'higher':44B 'host':23B 'infrastructur':19B 'instruct':88C 'known':53B 'known-exploit':52B 'let':39B 'list':48B 'local':41B 'log':28B,67C 'microsoft':1A,3A,16A,25B,64C 'per':86C 'privileg':7A,35B,45B,79C 'ransomwar':20B,62B 'requir':82C 'self':22B 'self-host':21B 'system':30B,69C 'tag':58B 'unspecifi':74C 'updat':85C 'use':60B 'user':42B 'vendor':87C 'vulner':9A,75C 'window':2A,4A,24B,26B,65C 'windows':17A","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2022-04-13T00:00:00+00:00","kev":{"dateAdded":"2022-04-13","dueDate":"2022-05-04","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Known"},"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2022-24521","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2022-24521","severity":null,"published_at":"2022-04-13T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T13:39:31+00:00","note":null},{"source":"epss","external_id":"CVE-2022-24521","url":"https://api.first.org/data/v1/epss?cve=CVE-2022-24521","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-2022-24521","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-24521","severity":null,"published_at":"2022-04-15T19:15:11+00:00","modified_at":"2026-06-17T04:32:02+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"}