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CVE-2021-27878

Estado: AnalizadaAlta (8.8)⚠ Explotación activa💥 Exploit

An issue was discovered in Veritas Backup Exec before 21.2. The communication between a client and an Agent requires successful authentication, which is typically completed over a secure TLS communication. However, due to a vulnerability in the SHA Authentication scheme, an attacker is able to gain unauthorized access and complete the authentication process. Subsequently, the client can execute data management protocol commands on the authenticated connection. The attacker could use one of these commands to execute an arbitrary command on the system using system privileges.

CVSS

Probabilidad de explotación (EPSS)

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

💥 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.

🎯 Técnicas ATT&CK

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

Vulnerabilidad en autenticación SHA permite acceso no autorizado a servicio remoto (Backup Exec) con posterior ejecución de comandos arbitrarios con privilegios del sistema. AV:N, PR:L, impacto crítico en confidencialidad, integridad y disponibilidad.

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

Vulnerability ScanningThreat Intelligence ProgramPrivileged Account ManagementNetwork SegmentationDisable or Remove Feature or ProgramApplication Isolation and Sandboxing

Tecnologías afectadas (1)

Veritas — Backup Exec

CWE

Referencias

JSON original (NVD)

Mostrar
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  "id": "CVE-2021-27878",
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      "value": "An issue was discovered in Veritas Backup Exec before 21.2. The communication between a client and an Agent requires successful authentication, which is typically completed over a secure TLS communication. However, due to a vulnerability in the SHA Authentication scheme, an attacker is able to gain unauthorized access and complete the authentication process. Subsequently, the client can execute data management protocol commands on the authenticated connection. The attacker could use one of these commands to execute an arbitrary command on the system using system privileges."
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      "value": "Se detectó un problema en Veritas Backup Exec versiones anteriores a 21.2. La comunicación entre un cliente y un agente requiere una autenticación con éxito, que generalmente se completa por medio de una comunicación TLS segura. Sin embargo, debido a una vulnerabilidad en el esquema de autenticación SHA, un atacante puede conseguir acceso no autorizado y completar el proceso de autenticación. Posteriormente, el cliente puede ejecutar comandos de protocolo de gestión de datos en la conexión autenticada. El atacante podría usar uno de estos comandos para ejecutar un comando arbitrario en el sistema usando privilegios system"
    }
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  "lastModified": "2026-06-17T03:45:33.063",
  "cisaActionDue": "2023-04-28",
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  "cisaRequiredAction": "Apply updates per vendor instructions.",
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