CVE-2021-26858
Estado: AnalizadaAlta (7.8)⚠ Explotación activa
Microsoft Exchange Server Remote Code Execution Vulnerability
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 94%
- Percentil entre todas las CVEs puntuadas: 100
- Fecha de la puntuación: 4/10/2026
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
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1203Exploitation for Client Executionexecution75 % - Impacto principal
T1059.001PowerShellexecution85 % - Impacto secundario
T1486Data Encrypted for Impactimpact80 % - Impacto secundario
T1565.001Stored Data Manipulationimpact70 %
AV:L + PR:N + UI:R sugiere escalada local con interacción; RCE confirmado y uso activo en ransomware (T1486, T1059) con riesgo de manipulación de datos (T1565).
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 (1)
CWE
- NVD-CWE-noinfo
Referencias
JSON original (NVD)
Mostrar
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