{"id":"CVE-2021-31961","aliases":["EUVD-2021-18833","GHSA-6q4f-qhgv-gf97"],"status":"published","title":"Windows InstallService Elevation of Privilege Vulnerability","description":"Windows InstallService Elevation of Privilege Vulnerability","severity":{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H/E:U/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00808,"percentile":0.57165,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-269"],"published":"2021-07-14T17:53:15Z","modified":"2026-08-10T18:31:33Z","products":[{"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 2019"},{"vendor":"microsoft","product":"windows server 2019 (server core installation)"},{"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"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-31961","tags":["vendor-advisory","patch"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31961","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-21-818/","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-31961"},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-21-818"},{"url":"https://github.com/advisories/GHSA-6q4f-qhgv-gf97"}],"sources":{"cve":[{"id":"CVE-2021-31961","title":"Windows InstallService Elevation of Privilege Vulnerability","description":"Windows InstallService Elevation of Privilege Vulnerability","status":"published","published":"2021-07-14T17:53:15Z","modified":"2026-08-10T15:11:30.709Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H/E:U/RL:O/RC:C","level":"medium","assessor":"cna"}],"updated_at":"2026-11-02T14:33:05.989686Z"}],"euvd":[{"id":"EUVD-2021-18833","description":"Windows InstallService Elevation of Privilege Vulnerability","status":"published","published":"2021-07-14T17:53:15Z","modified":"2026-08-10T15:11:30Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H/E:U/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-02T18:02:04.178454Z"}],"ghsa":[{"id":"GHSA-6q4f-qhgv-gf97","title":"Windows InstallService Elevation of Privilege Vulnerability","description":"Windows InstallService Elevation of Privilege Vulnerability","status":"published","published":"2022-05-24T19:07:56Z","modified":"2026-08-10T18:31:33Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","level":"medium"}],"cwes":["CWE-269"],"updated_at":"2026-11-02T15:10:14.704025Z"}],"nvd":[{"id":"CVE-2021-31961","description":"Windows InstallService Elevation of Privilege Vulnerability","status":"published","published":"2021-07-14T18:15:09.563Z","modified":"2026-08-10T16:17:35.8Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","level":"medium","assessor":"secondary"},{"version":"2.0","score":3.6,"vector":"AV:L/AC:L/Au:N/C:N/I:P/A:P","level":"low","assessor":"primary"}],"cwes":["CWE-269"],"updated_at":"2026-11-02T14:06:55.747384Z"}]}}