CVE-2021-33771
Estado: AnalizadaAlta (7.8)⚠ Explotación activa
Windows Kernel Elevation of Privilege Vulnerability
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 10%
- Percentil entre todas las CVEs puntuadas: 96
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
CISA KEV — explotada activamente
- Añadida al catálogo: 3/11/2021
- Plazo de remediación: 17/11/2021
- Uso conocido en ransomware: Unknown
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation95 % - Impacto principal
T1059Command and Scripting Interpreterexecution90 % - Impacto secundario
T1134Access Token Manipulationstealth · privilege escalation80 % - Impacto secundario
T1548Abuse Elevation Control Mechanismprivilege escalation85 %
Vulnerabilidad local del kernel Windows (AV:L, PR:L) permite escalada de privilegios (I:H, C:H) para ejecución con privilegios elevados, confirmado por KEV y vectores CVSS.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (14)
Microsoft — Windows 10 1507Microsoft — Windows 10 1607Microsoft — Windows 10 1809Microsoft — Windows 10 1909Microsoft — Windows 10 2004Microsoft — Windows 10 20h2Microsoft — Windows 10 21h1Microsoft — Windows 8.1Microsoft — Windows RT 8.1Microsoft — Windows Server 2004Microsoft — Windows Server 2012Microsoft — Windows Server 2016Microsoft — Windows Server 2019Microsoft — Windows Server 20h2
CWE
- NVD-CWE-noinfo
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2021-33771",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2021-33771",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "active"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2024-02-06T15:34:13.481047Z"
}
}
],
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 7.2,
"accessVector": "LOCAL",
"vectorString": "AV:L/AC:L/Au:N/C:C/I:C/A:C",
"authentication": "NONE",
"integrityImpact": "COMPLETE",
"accessComplexity": "LOW",
"availabilityImpact": "COMPLETE",
"confidentialityImpact": "COMPLETE"
},
"acInsufInfo": false,
"impactScore": 10,
"baseSeverity": "HIGH",
"obtainAllPrivilege": false,
"exploitabilityScore": 3.9,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "secure@microsoft.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
},
{
"type": "Secondary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"affected": [
{
"source": "secure@microsoft.com",
"affectedData": [
{
"vendor": "Microsoft",
"product": "Windows 10 Version 1507",
"versions": [
{
"status": "affected",
"version": "10.0.10240.0",
"lessThan": "10.0.10240.19003",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 1607",
"versions": [
{
"status": "affected",
"version": "10.0.14393.0",
"lessThan": "10.0.14393.4530",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 1809",
"versions": [
{
"status": "affected",
"version": "10.0.17763.0",
"lessThan": "10.0.17763.2061",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 1809",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.17763.2061",
"versionType": "custom"
}
],
"platforms": [
"ARM64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 1909",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.18363.1679",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"ARM64-based Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 2004",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.19041.1110",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"ARM64-based Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 20H2",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.19042.1110",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"ARM64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 21H1",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.19043.1110",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"ARM64-based Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 8.1",
"versions": [
{
"status": "affected",
"version": "6.3.0",
"lessThan": "6.3.9600.20069",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"ARM64-based Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2012 R2",
"versions": [
{
"status": "affected",
"version": "6.3.9600.0",
"lessThan": "6.3.9600.20069",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2012 R2 (Server Core installation)",
"versions": [
{
"status": "affected",
"version": "6.3.9600.0",
"lessThan": "6.3.9600.20069",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2016",
"versions": [
{
"status": "affected",
"version": "10.0.14393.0",
"lessThan": "10.0.14393.4530",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2016 (Server Core installation)",
"versions": [
{
"status": "affected",
"version": "10.0.14393.0",
"lessThan": "10.0.14393.4530",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2019",
"versions": [
{
"status": "affected",
"version": "10.0.17763.0",
"lessThan": "10.0.17763.2061",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2019 (Server Core installation)",
"versions": [
{
"status": "affected",
"version": "10.0.17763.0",
"lessThan": "10.0.17763.2061",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server version 2004",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.19041.1110",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server version 20H2",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.19042.1110",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
}
]
}
],
"published": "2021-07-14T18:15:10.483",
"references": [
{
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-33771",
"tags": [
"Patch",
"Vendor Advisory"
],
"source": "secure@microsoft.com"
},
{
"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33771",
"tags": [
"Patch",
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-33771",
"tags": [
"US Government Resource"
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Windows Kernel Elevation of Privilege Vulnerability"
},
{
"lang": "es",
"value": "Una vulnerabilidad de Elevación de Privilegios en Windows Kernel. Este ID de CVE es diferente de CVE-2021-31979, CVE-2021-34514"
}
],
"lastModified": "2026-08-10T19:58:46.650",
"cisaActionDue": "2021-11-17",
"cisaExploitAdd": "2021-11-03",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "0C51CD3A-E78B-4A0D-8716-4F2C0A79ED68",
"versionEndExcluding": "10.0.10240.19003"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9EEBF8AC-AB6E-4F62-811A-0E53721C78F5",
"versionEndExcluding": "10.0.14393.4530"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5BAABE12-C0E8-4E34-9EFE-18DD50C54B1D",
"versionEndExcluding": "10.0.17763.2061"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1909:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "1C9E359B-5719-48B1-BABB-618744C73388",
"versionEndExcluding": "10.0.18363.1679"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_2004:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "307C13CF-563B-46D1-9F2E-227AB9C40720",
"versionEndExcluding": "10.0.19041.1110"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9AEC53C7-C1CB-4FFB-8069-27604FB50F0B",
"versionEndExcluding": "10.0.19042.1110"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_21h1:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "765BA052-1B41-4CD3-98E6-F3750E0466E5",
"versionEndExcluding": "10.0.19043.1110"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E93068DB-549B-45AB-8E5C-00EB5D8B5CF8"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "C6CE5198-C498-4672-AF4C-77AB4BE06C5C"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2004:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A73D95E0-7290-4049-ACA6-7071B6ECAB8D",
"versionEndExcluding": "10.0.19041.1110"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2012:-:r2:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5F2558DF-2D1F-46BA-ABF1-08522D33268E"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9127CF36-6B37-4698-BB02-2AC6D853EB6F",
"versionEndExcluding": "10.0.14393.4530"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "77FA5A89-9F88-48FB-B632-76433EDBA95F",
"versionEndExcluding": "10.0.17763.2061"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "C210CB34-3DA4-4273-BF7C-F2692173E180",
"versionEndExcluding": "10.0.19042.1110"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "secure@microsoft.com",
"cisaRequiredAction": "Apply updates per vendor instructions.",
"cisaVulnerabilityName": "Microsoft Windows Kernel Privilege Escalation Vulnerability"
}