CVE-2021-28799

Estado: AnalizadaCrítica (9.8)⚠ Explotación activa

An improper authorization vulnerability has been reported to affect QNAP NAS running HBS 3 (Hybrid Backup Sync. ) If exploited, the vulnerability allows remote attackers to log in to a device. This issue affects: QNAP Systems Inc. HBS 3 versions prior to v16.0.0415 on QTS 4.5.2; versions prior to v3.0.210412 on QTS 4.3.6; versions prior to v3.0.210411 on QTS 4.3.4; versions prior to v3.0.210411 on QTS 4.3.3; versions prior to v16.0.0419 on QuTS hero h4.5.1; versions prior to v16.0.0419 on QuTScloud c4.5.1~c4.5.4. This issue does not affect: QNAP Systems Inc. HBS 2 . QNAP Systems Inc. HBS 1.3 .

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 9.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 78%
Percentil entre todas las CVEs puntuadas: 100
Fecha de la puntuación: 6/10/2026

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: 31/3/2022
Plazo de remediación: 21/4/2022
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.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access90 %
Impacto principalT1078.001 Default Accountsstealth · persistence · privilege escalation · initial access95 %

Vulnerabilidad de autorización insuficiente (CWE-285) en aplicación web expuesta (AV:N/AC:L/PR:N) que permite autenticarse remotamente sin credenciales legítimas, accediendo a datos sensibles del NAS.

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 Scanning Privileged Account Management Password Policies Network Segmentation Multi-factor Authentication Limit Access to Resource Over Network

Tecnologías afectadas (1)

Qnap — Hybrid Backup Sync

CWE

CWE-285
NVD-CWE-Other

Referencias

JSON original (NVD)

Mostrar

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