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CVE-2021-27877

Estado: AnalizadaCrítica (9.8)⚠ Explotación activa💥 Exploit

An issue was discovered in Veritas Backup Exec before 21.2. It supports multiple authentication schemes: SHA authentication is one of these. This authentication scheme is no longer used in current versions of the product, but hadn't yet been disabled. An attacker could remotely exploit this scheme to gain unauthorized access to an Agent and execute privileged commands.

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.

⚠️ 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.

Vulnerabilidad de aplicación web expuesta (Backup Exec) sin autenticación requerida (PR:N, UI:N) que permite ejecución remota de comandos privilegiados mediante esquema SHA débil conocido.

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

Privileged Account ManagementVulnerability ScanningPassword PoliciesNetwork SegmentationMulti-factor AuthenticationLimit Access to Resource Over Network

Tecnologías afectadas (1)

Veritas — Backup Exec

CWE

Referencias

JSON original (NVD)

Mostrar
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  "published": "2021-03-01T22:15:14.460",
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    },
    {
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      "value": "Se detectó un problema en Veritas Backup Exec versiones anteriores a 21.2. Admite múltiples esquemas de autenticación: la autenticación SHA es uno de ellos. Este esquema de autenticación ya no se utiliza en las versiones actuales del producto, pero aún no se ha desactivado. Un atacante podría explotar este esquema remotamente para conseguir acceso no autorizado a un agente y ejecutar comandos privilegiados"
    }
  ],
  "lastModified": "2026-06-17T03:45:32.920",
  "cisaActionDue": "2023-04-28",
  "cisaExploitAdd": "2023-04-07",
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  "cisaRequiredAction": "Apply updates per vendor instructions.",
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}