{"id":"CVE-2021-36948","kind":"vulnerability","aliases":["CVE-2021-36948"],"related":[],"title":"Microsoft Windows: Microsoft Windows Update Medic Service Privilege Escalation Vulnerability","description":"Microsoft Windows Update Medic Service contains an unspecified vulnerability that allows for privilege escalation.\n\nCISA required action: Apply updates per vendor instructions.","summary":"Microsoft Windows Update Medic Service has an unspecified flaw that lets a local user gain higher privileges. It is listed in CISA's Known Exploited Vulnerabilities catalog, so attackers are using it in the wild.","severity":"high","cvss":7.8,"epss":0.2327,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Microsoft Windows","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","infrastructure","windows"],"not_affected_if":["unknown"],"how_to_check":null,"fix":"Apply the Microsoft Windows updates per vendor instructions; the specific patched build is not stated in the sources.","status":"open","published_at":"2021-08-12T18:15:10+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:39:27+00:00","updated_at":"2026-10-23T21:57:34+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:39:27Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Microsoft Windows updates per vendor instructions; the specific patched build is not stated in the sources.","reach":"local","impact":"high","summary":"Microsoft Windows Update Medic Service has an unspecified flaw that lets a local user gain higher privileges. It is listed in CISA's Known Exploited Vulnerabilities catalog, so attackers are using it in the wild.","category":"infrastructure","who_cares":["windows"],"confidence":0.6,"needs_auth":"yes","worst_case":"local user becomes SYSTEM administrator on the Windows machine","analyst_note":"Find the Microsoft security update guide entry for CVE-2021-36948 to get the patched Windows builds and how to verify them.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["unknown"],"user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.000444,"input_tokens":2823,"output_tokens":324,"severity_before":"unknown"},"analyst_status":"queued","analyst_note":"Find the Microsoft security update guide entry for CVE-2021-36948 to get the patched Windows builds and how to verify them.","search":"'-2021':12A,15A '-36948':13A,16A 'action':73C 'allow':67C 'appli':74C 'attack':50B 'catalog':48B 'cisa':43B,71C 'contain':62C 'cve':11A,14A 'escal':9A,70C 'exploit':19B,46B 'flaw':30B 'gain':36B 'higher':37B 'infrastructur':20B 'instruct':78C 'known':45B 'let':32B 'list':41B 'local':34B 'medic':6A,25B,60C 'microsoft':1A,3A,17A,22B,57C 'per':76C 'privileg':8A,38B,69C 'requir':72C 'servic':7A,26B,61C 'unspecifi':29B,64C 'updat':5A,24B,59C,75C 'use':52B 'user':35B 'vendor':77C 'vulner':10A,47B,65C 'wild':56B 'window':2A,4A,21B,23B,58C 'windows':18A","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-08-12T18:15:10+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"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-2021-36948","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-36948","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":"2026-10-25T14:39:41+00:00","note":null},{"source":"epss","external_id":"CVE-2021-36948","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-36948","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-2021-36948","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-36948","severity":null,"published_at":"2021-08-12T18:15:10+00:00","modified_at":"2026-08-10T20:19:08+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"}