CVE-2021-21220

Estado: AnalizadaAlta (8.8)⚠ Explotación activa💥 Exploit

Una comprobación insuficiente de una entrada no confiable en V8 en Google Chrome versiones anteriores a e 89.0.4389.128, permitió a un atacante remoto explotar potencialmente una corrupción de la pila por medio de una página HTML diseñada

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Puntuación base: 8.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 70%
Percentil entre todas las CVEs puntuadas: 99
Fecha de la puntuación: 7/10/2026

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: 17/11/2021
Uso conocido en ransomware: Unknown

💥 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.

Módulo de Metasploit (exploit fiable y al alcance de cualquiera) · Google Chrome versions before 89.0.4389.128 V8 XOR Typer Out-Of-Bounds Access RCE
Prueba de concepto en GitHub (no verificada) · Lista de pruebas de concepto en GitHub

⚠️ 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.

ExplotaciónT1203 Exploitation for Client Executionexecution85 %
Impacto principalT1059 Command and Scripting Interpreterexecution80 %
Impacto secundarioT1565.001 Stored Data Manipulationimpact70 %

Vector AV:N/UI:R apunta a explotación en cliente con interacción (T1203). Heap corruption en V8 permite ejecución de código arbitrario (T1059) y potencial manipulación de datos (T1565.001) via HTML crafted.

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

Restrict Web-Based Content Restrict File and Directory Permissions Privileged Account Management Remote Data Storage Limit Software Installation Execution Prevention

Tecnologías afectadas (2)

Fedoraproject — Fedora Google — Chrome

CWE

CWE-787
CWE-787

Referencias

JSON original (NVD)

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    },
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