CVE-2021-31207

Estado: AnalizadaMedia (6.6)⚠ Explotación activa

Microsoft Exchange Server Security Feature Bypass Vulnerability

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 6.6

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 100%
Percentil entre todas las CVEs puntuadas: 100
Fecha de la puntuación: 29/9/2026

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: Known

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1210 Exploitation of Remote Serviceslateral movement85 %
Impacto principalT1505.003 Web Shellpersistence80 %
Impacto secundarioT1059.001 PowerShellexecution75 %

AV:N sin privilegios iniciales en Exchange Server remoto (T1210). CWE-434 permite upload de archivos maliciosos que resultan en webshell (T1505.003) y ejecución de código (T1059.001). KEV activa por ransomware confirma explotación en cadenas de ataque reales.

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

Disable or Remove Feature or Program Privileged Account Management Vulnerability Scanning User Account Management Threat Intelligence Program Network Segmentation

Tecnologías afectadas (1)

Microsoft — Exchange Server

CWE

CWE-434
CWE-434

Referencias

JSON original (NVD)

Mostrar

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