CVE-2021-34527
Estado: AnalizadaAlta (8.8)⚠ Explotación activa💥 Exploit
A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged file operations. An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. UPDATE July 7, 2021: The security update for Windows Server 2012, Windows Server 2016 and Windows 10, Version 1607 have been released. Please see the Security Updates table for the applicable update for your system.
Leer descripción completaMostrar menos
We recommend that you install these updates immediately. If you are unable to install these updates, see the FAQ and Workaround sections in this CVE for information on how to help protect your system from this vulnerability. In addition to installing the updates, in order to secure your system, you must confirm that the following registry settings are set to 0 (zero) or are not defined (Note: These registry keys do not exist by default, and therefore are already at the secure setting.), also that your Group Policy setting are correct (see FAQ):
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Printers\PointAndPrint NoWarningNoElevationOnInstall = 0 (DWORD) or not defined (default setting) UpdatePromptSettings = 0 (DWORD) or not defined (default setting)
Having NoWarningNoElevationOnInstall set to 1 makes your system vulnerable by design. UPDATE July 6, 2021: Microsoft has completed the investigation and has released security updates to address this vulnerability. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. If you are unable to install these updates, see the FAQ and Workaround sections in this CVE for information on how to help protect your system from this vulnerability. See also KB5005010: Restricting installation of new printer drivers after applying the July 6, 2021 updates. Note that the security updates released on and after July 6, 2021 contain protections for CVE-2021-1675 and the additional remote code execution exploit in the Windows Print Spooler service known as “PrintNightmare”, documented in CVE-2021-34527.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 8.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 100%
- Percentil entre todas las CVEs puntuadas: 100
- Fecha de la puntuación: 7/10/2026
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: 3/5/2022
- Uso conocido en ransomware: Known
💥 Exploits públicos
Hay código de explotación o plantillas de detección públicos. No es lo mismo que explotación activa confirmada (KEV), pero aumenta el riesgo: parchee con prioridad.
- Módulo de Metasploit (exploit fiable y al alcance de cualquiera) · Print Spooler Remote DLL Injection
- Prueba de concepto en GitHub (no verificada) · Lista de pruebas de concepto en GitHub
⚠️ Las pruebas de concepto de GitHub no están verificadas: algunas son falsas o contienen malware. No las ejecute nunca fuera de un laboratorio aislado.
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1210Exploitation of Remote Serviceslateral movement90 % - Impacto principal
T1059Command and Scripting Interpreterexecution95 % - Impacto secundario
T1078.002Domain Accountsstealth · persistence · privilege escalation · initial access85 % - Impacto secundario
T1548.004Elevated Execution with Promptprivilege escalation90 %
Explotación remota del Print Spooler (T1210) con autenticación requerida (PR:L). Logra ejecución de código con privilegios SYSTEM (T1059), escalada de privilegios (T1548.004) e instalación de cuentas con derechos completos (T1078.002).
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 (15)
Microsoft — Windows 10 1507Microsoft — Windows 10 1607Microsoft — Windows 10 1809Microsoft — Windows 10 20h2Microsoft — Windows 10 21h2Microsoft — Windows 10 22h2Microsoft — Windows 11 21h2Microsoft — Windows 11 22h2Microsoft — Windows RT 8.1Microsoft — Windows Server 2008Microsoft — Windows Server 2012Microsoft — Windows Server 2016Microsoft — Windows Server 2019Microsoft — Windows Server 2022Microsoft — Windows Server 20h2
CWE
- NVD-CWE-noinfo
Referencias
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34527
- http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34527
- https://www.kb.cert.org/vuls/id/383432
- https://www.vicarius.io/vsociety/posts/cve-2021-34527-printnightmare-detection-script
- https://www.vicarius.io/vsociety/posts/cve-2021-34527-printnightmare-mitigation-script
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34527
JSON original (NVD)
Mostrar
{
"id": "CVE-2021-34527",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2021-34527",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "active"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2024-01-24T16:04:14.042095Z"
}
}
],
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 9,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:L/Au:S/C:C/I:C/A:C",
"authentication": "SINGLE",
"integrityImpact": "COMPLETE",
"accessComplexity": "LOW",
"availabilityImpact": "COMPLETE",
"confidentialityImpact": "COMPLETE"
},
"acInsufInfo": false,
"impactScore": 10,
"baseSeverity": "HIGH",
"obtainAllPrivilege": false,
"exploitabilityScore": 8,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "secure@microsoft.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 8.8,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/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": 2.8
},
{
"type": "Secondary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 8.8,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/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": 2.8
}
]
},
"affected": [
{
"source": "secure@microsoft.com",
"affectedData": [
{
"vendor": "Microsoft",
"product": "Windows 10 Version 1507",
"versions": [
{
"status": "affected",
"version": "10.0.10240.0",
"lessThan": "10.0.10240.18969",
"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": "10.0.14393.4470",
"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": "10.0.17763.2029",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 1809",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.17763.2029",
"versionType": "custom"
}
],
"platforms": [
"ARM64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 20H2",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.19042.1083",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"ARM64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 21H2",
"versions": [
{
"status": "affected",
"version": "10.0.19044.0",
"lessThan": "10.0.19044.1415",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"ARM64-based Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 10 Version 22H2",
"versions": [
{
"status": "affected",
"version": "10.0.19045.0",
"lessThan": "10.0.19045.2251",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"ARM64-based Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 11 version 21H2",
"versions": [
{
"status": "affected",
"version": "10.0.22000.0",
"lessThan": "10.0.22000.318",
"versionType": "custom"
}
],
"platforms": [
"ARM64-based Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 11 version 22H2",
"versions": [
{
"status": "affected",
"version": "10.0.22621.0",
"lessThan": "10.0.22621.674",
"versionType": "custom"
}
],
"platforms": [
"ARM64-based Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows 8.1",
"versions": [
{
"status": "affected",
"version": "6.3.0",
"lessThan": "6.3.9600.20046",
"versionType": "custom"
}
],
"platforms": [
"ARM64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2008 R2 Service Pack 1",
"versions": [
{
"status": "affected",
"version": "6.1.7601.0",
"lessThan": "6.1.7601.25633",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2008 R2 Service Pack 1 (Server Core installation)",
"versions": [
{
"status": "affected",
"version": "6.1.7601.0",
"lessThan": "6.1.7601.25633",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2008 Service Pack 2",
"versions": [
{
"status": "affected",
"version": "6.0.6003.0",
"lessThan": "6.0.6003.21138",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2008 Service Pack 2 (Server Core installation)",
"versions": [
{
"status": "affected",
"version": "6.0.6003.0",
"lessThan": "6.0.6003.21138",
"versionType": "custom"
}
],
"platforms": [
"32-bit Systems",
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2012",
"versions": [
{
"status": "affected",
"version": "6.2.9200.0",
"lessThan": "6.2.9200.23383",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2012 (Server Core installation)",
"versions": [
{
"status": "affected",
"version": "6.2.9200.0",
"lessThan": "6.2.9200.23383",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2012 R2",
"versions": [
{
"status": "affected",
"version": "6.3.9600.0",
"lessThan": "6.3.9600.20046",
"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": "6.3.9600.20046",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2016",
"versions": [
{
"status": "affected",
"version": "10.0.14393.0",
"lessThan": "10.0.14393.4470",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2016 (Server Core installation)",
"versions": [
{
"status": "affected",
"version": "10.0.14393.0",
"lessThan": "10.0.14393.4470",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2019",
"versions": [
{
"status": "affected",
"version": "10.0.17763.0",
"lessThan": "10.0.17763.2029",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2019 (Server Core installation)",
"versions": [
{
"status": "affected",
"version": "10.0.17763.0",
"lessThan": "10.0.17763.2029",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server 2022",
"versions": [
{
"status": "affected",
"version": "10.0.20348.0",
"lessThan": "10.0.20348.230",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
},
{
"vendor": "Microsoft",
"product": "Windows Server version 20H2",
"versions": [
{
"status": "affected",
"version": "10.0.0",
"lessThan": "10.0.19042.1083",
"versionType": "custom"
}
],
"platforms": [
"x64-based Systems"
]
}
]
}
],
"published": "2021-07-02T22:15:08.757",
"references": [
{
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34527",
"tags": [
"Patch",
"Vendor Advisory"
],
"source": "secure@microsoft.com"
},
{
"url": "http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html",
"tags": [
"Exploit",
"Third Party Advisory",
"VDB Entry"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34527",
"tags": [
"Mitigation",
"Patch",
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.kb.cert.org/vuls/id/383432",
"tags": [
"Third Party Advisory",
"US Government Resource"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.vicarius.io/vsociety/posts/cve-2021-34527-printnightmare-detection-script",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.vicarius.io/vsociety/posts/cve-2021-34527-printnightmare-mitigation-script",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34527",
"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": "A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged file operations. An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.\nUPDATE July 7, 2021: The security update for Windows Server 2012, Windows Server 2016 and Windows 10, Version 1607 have been released. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. If you are unable to install these updates, see the FAQ and Workaround sections in this CVE for information on how to help protect your system from this vulnerability.\nIn addition to installing the updates, in order to secure your system, you must confirm that the following registry settings are set to 0 (zero) or are not defined (Note: These registry keys do not exist by default, and therefore are already at the secure setting.), also that your Group Policy setting are correct (see FAQ):\n\nHKEY_LOCAL_MACHINE\\SOFTWARE\\Policies\\Microsoft\\Windows NT\\Printers\\PointAndPrint\nNoWarningNoElevationOnInstall = 0 (DWORD) or not defined (default setting)\nUpdatePromptSettings = 0 (DWORD) or not defined (default setting)\n\nHaving NoWarningNoElevationOnInstall set to 1 makes your system vulnerable by design.\nUPDATE July 6, 2021: Microsoft has completed the investigation and has released security updates to address this vulnerability. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. If you are unable to install these updates, see the FAQ and Workaround sections in this CVE for information on how to help protect your system from this vulnerability. See also KB5005010: Restricting installation of new printer drivers after applying the July 6, 2021 updates.\nNote that the security updates released on and after July 6, 2021 contain protections for CVE-2021-1675 and the additional remote code execution exploit in the Windows Print Spooler service known as “PrintNightmare”, documented in CVE-2021-34527."
},
{
"lang": "es",
"value": "Una vulnerabilidad en la ejecución de código remota de Windows Print Spooler"
}
],
"lastModified": "2026-08-10T20:15:22.807",
"cisaActionDue": "2022-05-03",
"cisaExploitAdd": "2021-11-03",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "8C882409-BB85-490B-9D50-571B16C0DE86",
"versionEndExcluding": "10.0.10240.18969"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "217CDA93-36DA-49AE-9B8F-61D2E155B4F3",
"versionEndExcluding": "10.0.14393.4470"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "B9D38F0E-B058-44EE-9C75-A96EBEA360A6",
"versionEndExcluding": "10.0.17763.2029"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "413EBEFB-B185-4D3E-840B-9F37AA041229",
"versionEndExcluding": "10.0.19042.1083"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "4B773592-2AC2-48CD-A6B3-98D2632A2F88",
"versionEndExcluding": "10.0.19044.1415"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "71F26E89-0870-4C4A-81FE-F9F793A9E706",
"versionEndExcluding": "10.0.19045.2251"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_21h2:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "193B0B19-6DD7-4DF3-B133-D66B27C34E9C",
"versionEndExcluding": "10.0.22000.318"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_22h2:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9DEC0AE5-324C-4117-ADFD-D8425D01C575",
"versionEndExcluding": "10.0.22621.674"
},
{
"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_2008:-:sp2:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5F422A8C-2C4E-42C8-B420-E0728037E15C"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*",
"vulnerable": true,
"matchCriteriaId": "AF07A81D-12E5-4B1D-BFF9-C8D08C32FF4F"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A7DF96F8-BA6A-4780-9CA3-F719B3F81074"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "DB18C4CE-5917-401E-ACF7-2747084FD36E"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E90B2736-F3AC-4CA9-9817-1CCC320B854D",
"versionEndExcluding": "10.0.14393.4470"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "81CDECCC-4AB5-406B-B265-3C1760D01339",
"versionEndExcluding": "10.0.17763.2029"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "0663409D-4AE8-4BD9-85FE-9EAED15AE9DB",
"versionEndExcluding": "10.0.20348.230"
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5B0C7DE0-3E5C-4112-A7AD-FC195C3E2E62",
"versionEndExcluding": "10.0.19042.1083"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "secure@microsoft.com",
"cisaRequiredAction": "Apply updates per vendor instructions.",
"cisaVulnerabilityName": "Microsoft Windows Print Spooler Remote Code Execution Vulnerability"
}