{"id":"CVE-2021-38634","aliases":["EUVD-2021-25073","GHSA-p3jw-cchq-r2fw"],"status":"published","title":"Microsoft Windows Update Client Elevation of Privilege Vulnerability","description":"Microsoft Windows Update Client Elevation of Privilege Vulnerability","severity":{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.0087,"percentile":0.59297,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-269"],"published":"2021-09-15T11:23:56Z","modified":"2026-08-10T18:31:08Z","products":[{"vendor":"microsoft","product":"windows 10 version 1507"},{"vendor":"microsoft","product":"windows 10 version 1607"},{"vendor":"microsoft","product":"windows 10 version 1809"},{"vendor":"microsoft","product":"windows 10 version 1909"},{"vendor":"microsoft","product":"windows 10 version 2004"},{"vendor":"microsoft","product":"windows 10 version 20h2"},{"vendor":"microsoft","product":"windows 10 version 21h1"},{"vendor":"microsoft","product":"windows server 2016"},{"vendor":"microsoft","product":"windows server 2016 (server core installation)"},{"vendor":"microsoft","product":"windows server 2019"},{"vendor":"microsoft","product":"windows server 2019 (server core installation)"},{"vendor":"microsoft","product":"windows server 2022"},{"vendor":"microsoft","product":"windows server version 2004"},{"vendor":"microsoft","product":"windows server version 20h2"},{"vendor":"microsoft","product":"windows_10"},{"vendor":"microsoft","product":"windows_server_2016"},{"vendor":"microsoft","product":"windows_server_2019"},{"vendor":"microsoft","product":"windows_server_2022"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-38634","tags":["vendor-advisory","patch"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38634","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-21-1075/","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-38634"},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-21-1075"},{"url":"https://github.com/advisories/GHSA-p3jw-cchq-r2fw"}],"sources":{"cve":[{"id":"CVE-2021-38634","title":"Microsoft Windows Update Client Elevation of Privilege Vulnerability","description":"Microsoft Windows Update Client Elevation of Privilege Vulnerability","status":"published","published":"2021-09-15T11:23:56Z","modified":"2026-08-10T15:10:49.964Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna"}],"updated_at":"2026-11-02T14:33:07.349244Z"}],"euvd":[{"id":"EUVD-2021-25073","description":"Microsoft Windows Update Client Elevation of Privilege Vulnerability","status":"published","published":"2021-09-15T11:23:56Z","modified":"2026-08-10T15:10:49Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H/E:U/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-02T18:02:05.005873Z"}],"ghsa":[{"id":"GHSA-p3jw-cchq-r2fw","title":"Microsoft Windows Update Client Elevation of Privilege Vulnerability","description":"Microsoft Windows Update Client Elevation of Privilege Vulnerability","status":"published","published":"2022-05-24T19:14:44Z","modified":"2026-08-10T18:31:08Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"high"}],"cwes":["CWE-269"],"updated_at":"2026-11-02T15:10:14.704025Z"}],"nvd":[{"id":"CVE-2021-38634","description":"Microsoft Windows Update Client Elevation of Privilege Vulnerability","status":"published","published":"2021-09-15T12:15:14.547Z","modified":"2026-08-10T16:18:08.16Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"2.0","score":7.2,"vector":"AV:L/AC:L/Au:N/C:C/I:C/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-269"],"updated_at":"2026-11-02T14:06:58.502206Z"}]}}