CVE-2021-38634 - Vulnerability Details - OpenCVE

Microsoft Windows Update Client Elevation of Privilege Vulnerability

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

Access Vector Local

Access Complexity Low

Authentication None

Confidentiality Impact Complete

Integrity Impact Complete

Availability Impact Complete

This CVE is not in the KEV list.

The EPSS score is 0.0081.

Key SSVC decision points have not yet been added.

Vendors	Products
Microsoft	Windows 10 Windows 10 1507 Windows 10 1607 Windows 10 1809 Windows 10 1909 Windows 10 20h2 Windows 10 21h1 Windows Server 2004 Windows Server 2016 Windows Server 2019 Windows Server 2022 Windows Server 20h2

Configuration 1 [-]

OR	cpe:2.3:o:microsoft:windows_10:-:::::::*
	cpe:2.3:o:microsoft:windows_10:20h2:::::::*
	cpe:2.3:o:microsoft:windows_10:21h1:::::::*
	cpe:2.3:o:microsoft:windows_10:1607:::::::*
	cpe:2.3:o:microsoft:windows_10:1809:::::::*
	cpe:2.3:o:microsoft:windows_10:1909:::::::*
	cpe:2.3:o:microsoft:windows_10:2004:::::::*
	cpe:2.3:o:microsoft:windows_server_2016:-:::::::*
	cpe:2.3:o:microsoft:windows_server_2016:20h2:::::::*
	cpe:2.3:o:microsoft:windows_server_2016:2004:::::::*
	cpe:2.3:o:microsoft:windows_server_2019:-:::::::*
	cpe:2.3:o:microsoft:windows_server_2022:-:::::::*

No data.

No data.

References

Link	Providers
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38634
https://www.zerodayinitiative.com/advisories/ZDI-21-1075/

History

No history.

MITRE

Status: PUBLISHED

Assigner: microsoft

Published: 2021-09-15T11:23:56.000Z

Updated: 2024-08-04T01:44:23.537Z

Reserved: 2021-08-13T00:00:00.000Z

Link: CVE-2021-38634

Vulnrichment

No data.

NVD

Status : Modified

Published: 2021-09-15T12:15:14.547

Modified: 2026-06-17T04:02:29.250

Link: CVE-2021-38634

Redhat

No data.

OpenCVE Enrichment

No data.

{"containers": {"cna": {"title": "Microsoft Windows Update Client Elevation of Privilege Vulnerability", "datePublic": "2021-09-14T07:00:00.000Z", "affected": [{"vendor": "Microsoft", "product": "Windows 10 Version 1809", "cpes": ["cpe:2.3:o:microsoft:windows_10_1809:10.0.17763.2183:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_1809:10.0.17763.2183:*:*:*:*:*:x64:*", "cpe:2.3:o:microsoft:windows_10_1809:10.0.17763.2183:*:*:*:*:*:arm64:*"], "platforms": ["32-bit Systems", "x64-based Systems", "ARM64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.17763.2183", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2019", "cpes": ["cpe:2.3:o:microsoft:windows_server_2019:10.0.17763.2183:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.17763.2183", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2019 (Server Core installation)", "cpes": ["cpe:2.3:o:microsoft:windows_server_2019:10.0.17763.2183:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.17763.2183", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 10 Version 1909", "cpes": ["cpe:2.3:o:microsoft:windows_10_1909:10.0.18363.1801:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_1909:10.0.18363.1801:*:*:*:*:*:x64:*", "cpe:2.3:o:microsoft:windows_10_1809:10.0.18363.1801:*:*:*:*:*:x64:*"], "platforms": ["32-bit Systems", "x64-based Systems", "ARM64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.18363.1801", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 10 Version 21H1", "cpes": ["cpe:2.3:o:microsoft:windows_10_21H1:10.0.19043.1237:*:*:*:*:*:x64:*", "cpe:2.3:o:microsoft:windows_10_21H1:10.0.19043.1237:*:*:*:*:*:arm64:*", "cpe:2.3:o:microsoft:windows_10_21H1:10.0.19043.1237:*:*:*:*:*:x86:*"], "platforms": ["x64-based Systems", "ARM64-based Systems", "32-bit Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.19043.1237", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2022", "cpes": ["cpe:2.3:o:microsoft:windows_server_2022:10.0.20348.230:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.20348.230", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 10 Version 2004", "cpes": ["cpe:2.3:o:microsoft:windows_10_1809:10.0.19041.1237:*:*:*:*:*:x64:*"], "platforms": ["32-bit Systems", "ARM64-based Systems", "x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.19041.1237", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server version 2004", "cpes": ["cpe:2.3:o:microsoft:windows_server_2004:10.0.19041.1237:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.19041.1237", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 10 Version 20H2", "cpes": ["cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.1237:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.1237:*:*:*:*:*:arm64:*"], "platforms": ["32-bit Systems", "ARM64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.19042.1237", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server version 20H2", "cpes": ["cpe:2.3:o:microsoft:windows_server_20H2:10.0.19042.1237:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.19042.1237", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 10 Version 1507", "cpes": ["cpe:2.3:o:microsoft:windows_10_1507:10.0.10240.19060:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_1507:10.0.10240.19060:*:*:*:*:*:x64:*"], "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.10240.19060", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows 10 Version 1607", "cpes": ["cpe:2.3:o:microsoft:windows_10_1607:10.0.14393.4651:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_1607:10.0.14393.4651:*:*:*:*:*:x64:*"], "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.14393.4651", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2016", "cpes": ["cpe:2.3:o:microsoft:windows_server_2016:10.0.14393.4651:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.14393.4651", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Windows Server 2016 (Server Core installation)", "cpes": ["cpe:2.3:o:microsoft:windows_server_2016:10.0.14393.4651:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "versions": [{"version": "10.0.0", "lessThan": "10.0.14393.4651", "versionType": "custom", "status": "affected"}]}], "descriptions": [{"value": "Microsoft Windows Update Client Elevation of Privilege Vulnerability", "lang": "en-US"}], "problemTypes": [{"descriptions": [{"description": "Elevation of Privilege", "lang": "en-US", "type": "Impact"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2023-12-28T19:37:15.836Z"}, "references": [{"tags": ["x_refsource_MISC"], "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38634"}, {"tags": ["x_refsource_MISC"], "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-1075/"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en-US", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "baseSeverity": "HIGH", "baseScore": 7.1, "vectorString": "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"}}]}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T01:44:23.537Z"}, "title": "CVE Program Container", "references": [{"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38634"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-1075/"}]}]}, "cveMetadata": {"assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "assignerShortName": "microsoft", "cveId": "CVE-2021-38634", "datePublished": "2021-09-15T11:23:56.000Z", "dateReserved": "2021-08-13T00:00:00.000Z", "dateUpdated": "2024-08-04T01:44:23.537Z", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.1"}

{"affected": [{"affectedData": [{"cpes": ["cpe:2.3:o:microsoft:windows_10_1809:10.0.17763.2183:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_1809:10.0.17763.2183:*:*:*:*:*:x64:*", "cpe:2.3:o:microsoft:windows_10_1809:10.0.17763.2183:*:*:*:*:*:arm64:*"], "platforms": ["32-bit Systems", "x64-based Systems", "ARM64-based Systems"], "product": "Windows 10 Version 1809", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.17763.2183", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_server_2019:10.0.17763.2183:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Windows Server 2019", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.17763.2183", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_server_2019:10.0.17763.2183:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Windows Server 2019 (Server Core installation)", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.17763.2183", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_10_1909:10.0.18363.1801:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_1909:10.0.18363.1801:*:*:*:*:*:x64:*", "cpe:2.3:o:microsoft:windows_10_1809:10.0.18363.1801:*:*:*:*:*:x64:*"], "platforms": ["32-bit Systems", "x64-based Systems", "ARM64-based Systems"], "product": "Windows 10 Version 1909", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.18363.1801", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_10_21H1:10.0.19043.1237:*:*:*:*:*:x64:*", "cpe:2.3:o:microsoft:windows_10_21H1:10.0.19043.1237:*:*:*:*:*:arm64:*", "cpe:2.3:o:microsoft:windows_10_21H1:10.0.19043.1237:*:*:*:*:*:x86:*"], "platforms": ["x64-based Systems", "ARM64-based Systems", "32-bit Systems"], "product": "Windows 10 Version 21H1", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.19043.1237", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_server_2022:10.0.20348.230:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Windows Server 2022", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.20348.230", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_10_1809:10.0.19041.1237:*:*:*:*:*:x64:*"], "platforms": ["32-bit Systems", "ARM64-based Systems", "x64-based Systems"], "product": "Windows 10 Version 2004", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.19041.1237", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_server_2004:10.0.19041.1237:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Windows Server version 2004", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.19041.1237", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.1237:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_20H2:10.0.19042.1237:*:*:*:*:*:arm64:*"], "platforms": ["32-bit Systems", "ARM64-based Systems"], "product": "Windows 10 Version 20H2", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.19042.1237", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_server_20H2:10.0.19042.1237:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Windows Server version 20H2", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.19042.1237", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_10_1507:10.0.10240.19060:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_1507:10.0.10240.19060:*:*:*:*:*:x64:*"], "platforms": ["32-bit Systems", "x64-based Systems"], "product": "Windows 10 Version 1507", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.10240.19060", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_10_1607:10.0.14393.4651:*:*:*:*:*:x86:*", "cpe:2.3:o:microsoft:windows_10_1607:10.0.14393.4651:*:*:*:*:*:x64:*"], "platforms": ["32-bit Systems", "x64-based Systems"], "product": "Windows 10 Version 1607", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.14393.4651", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_server_2016:10.0.14393.4651:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Windows Server 2016", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.14393.4651", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}, {"cpes": ["cpe:2.3:o:microsoft:windows_server_2016:10.0.14393.4651:*:*:*:*:*:*:*"], "platforms": ["x64-based Systems"], "product": "Windows Server 2016 (Server Core installation)", "vendor": "Microsoft", "versions": [{"lessThan": "10.0.14393.4651", "status": "affected", "version": "10.0.0", "versionType": "custom"}]}], "source": "secure@microsoft.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:*", "matchCriteriaId": "21540673-614A-4D40-8BD7-3F07723803B0", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*", "matchCriteriaId": "9E2C378B-1507-4C81-82F6-9F599616845A", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:*:*", "matchCriteriaId": "FAE4278F-71A7-43E9-8F79-1CBFAE71D730", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*", "matchCriteriaId": "E01A4CCA-4C43-46E0-90E6-3E4DBFBACD64", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*", "matchCriteriaId": "6B8F3DD2-A145-4AF1-8545-CC42892DA3D1", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:*", "matchCriteriaId": "E9273B95-20ED-4547-B0A8-95AD15B30372", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:*", "matchCriteriaId": "AAE74AF3-C559-4645-A6C0-25C3D647AAC8", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*", "matchCriteriaId": "041FF8BA-0B12-4A1F-B4BF-9C4F33B7C1E7", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:*", "matchCriteriaId": "4A190388-AA82-4504-9D5A-624F23268C9F", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*", "matchCriteriaId": "0B60D940-80C7-49F0-8F4E-3F99AC15FA82", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*", "matchCriteriaId": "DB79EE26-FC32-417D-A49C-A1A63165A968", "vulnerable": true}, {"criteria": "cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:*", "matchCriteriaId": "821614DD-37DD-44E2-A8A4-FE8D23A33C3C", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Microsoft Windows Update Client Elevation of Privilege Vulnerability"}, {"lang": "es", "value": "Una Vulnerabilidad de Elevaci\u00f3n de Privilegios en Microsoft Windows Update Client"}], "id": "CVE-2021-38634", "lastModified": "2026-06-17T04:02:29.250", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "HIGH", "cvssData": {"accessComplexity": "LOW", "accessVector": "LOCAL", "authentication": "NONE", "availabilityImpact": "COMPLETE", "baseScore": 7.2, "confidentialityImpact": "COMPLETE", "integrityImpact": "COMPLETE", "vectorString": "AV:L/AC:L/Au:N/C:C/I:C/A:C", "version": "2.0"}, "exploitabilityScore": 3.9, "impactScore": 10.0, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": false}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.2, "source": "secure@microsoft.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Secondary"}]}, "published": "2021-09-15T12:15:14.547", "references": [{"source": "secure@microsoft.com", "tags": ["Patch", "Vendor Advisory"], "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38634"}, {"source": "secure@microsoft.com", "tags": ["Third Party Advisory", "VDB Entry"], "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-1075/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Vendor Advisory"], "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38634"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Third Party Advisory", "VDB Entry"], "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-1075/"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-269"}], "source": "nvd@nist.gov", "type": "Primary"}]}