{"id":"CVE-2021-1732","kind":"vulnerability","aliases":["CVE-2021-1732"],"related":[],"title":"Microsoft Win32k: Microsoft Win32k Privilege Escalation Vulnerability","description":"Microsoft Win32k contains an unspecified vulnerability that allows for privilege escalation.\n\nCISA required action: Apply updates per vendor instructions.","summary":"Microsoft Win32k, the Windows kernel graphics driver, has a privilege escalation flaw that lets a local user gain higher system rights. CISA lists it as actively exploited, and the KEV entry notes use in ransomware campaigns.","severity":"high","cvss":7.8,"epss":0.78376,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Microsoft Win32k","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","infrastructure","microsoft-windows","ransomware","windows"],"not_affected_if":["patched-windows"],"how_to_check":null,"fix":"Apply the Microsoft security update for CVE-2021-1732 per vendor instructions (CISA required action). Exact patched Windows builds are not stated in the sources.","status":"open","published_at":"2021-02-25T23:15:13+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:43:36+00:00","updated_at":"2026-10-23T21:57:34+00:00","category":"infrastructure","confidence":0.7,"triage":{"at":"2026-10-23T21:43:36Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Microsoft security update for CVE-2021-1732 per vendor instructions (CISA required action). Exact patched Windows builds are not stated in the sources.","reach":"local","impact":"high","summary":"Microsoft Win32k, the Windows kernel graphics driver, has a privilege escalation flaw that lets a local user gain higher system rights. CISA lists it as actively exploited, and the KEV entry notes use in ransomware campaigns.","category":"infrastructure","who_cares":["windows","microsoft-windows"],"confidence":0.7,"needs_auth":"yes","worst_case":"local user gains SYSTEM privileges on the Windows machine","analyst_note":"Find the Microsoft advisory for CVE-2021-1732 and the list of patched Windows builds, plus how to check installed KB status; the sources give none.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["patched-windows"],"user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.000464,"input_tokens":2818,"output_tokens":364,"severity_before":"unknown"},"analyst_status":"queued","analyst_note":"Find the Microsoft advisory for CVE-2021-1732 and the list of patched Windows builds, plus how to check installed KB status; the sources give none.","search":"'-1732':10A,13A '-2021':9A,12A 'action':72C 'activ':48B 'allow':66C 'appli':73C 'campaign':58B 'cisa':44B,70C 'contain':61C 'cve':8A,11A 'driver':29B 'entri':53B 'escal':6A,33B,69C 'exploit':16B,49B 'flaw':34B 'gain':40B 'graphic':28B 'higher':41B 'infrastructur':17B 'instruct':77C 'kernel':27B 'kev':52B 'let':36B 'list':45B 'local':38B 'microsoft':1A,3A,14A,19B,23B,59C 'microsoft-window':18B 'note':54B 'per':75C 'privileg':5A,32B,68C 'ransomwar':21B,57B 'requir':71C 'right':43B 'system':42B 'unspecifi':63C 'updat':74C 'use':55B 'user':39B 'vendor':76C 'vulner':7A,64C 'win32k':2A,4A,15A,24B,60C 'window':20B,22B,26B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-02-25T23:15:13+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","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-2021-1732","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-1732","severity":null,"published_at":"2021-11-03T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T12:39:25+00:00","note":null},{"source":"epss","external_id":"CVE-2021-1732","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-1732","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2021-1732","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-1732","severity":null,"published_at":"2021-02-25T23:15:13+00:00","modified_at":"2026-08-12T05:17:32+00:00","first_seen_at":"2026-10-23T21:57:34+00:00","fetched_at":"2026-10-23T21:57:34+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"}