CVE-2025-20241
Estado: AplazadaAlta (7.4)—
A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) feature of Cisco NX-OS Software for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, adjacent attacker to cause the IS-IS process to unexpectedly restart, which could cause an affected device to reload.
This vulnerability is due to insufficient input validation when parsing an ingress IS-IS packet. An attacker could exploit this vulnerability by sending a crafted IS-IS packet to an affected device.
Leer descripción completaMostrar menos
A successful exploit could allow the attacker to cause the unexpected restart of the IS-IS process, which could cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- Puntuación base: 7.4
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.28%
- Percentil entre todas las CVEs puntuadas: 18
- 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).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1210Exploitation of Remote Serviceslateral movement85 % - Impacto principal
T1499.004Application or System Exploitationimpact90 %
Vector AV:A (red adyacente) sin autenticación requiere T1210. La vulnerabilidad causa reinicio inesperado del proceso IS-IS y recarga del dispositivo, DoS explícito (CWE-733, flood de recursos).
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 (3)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-733
Referencias
JSON original (NVD)
Mostrar
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"published": "2025-08-27T17:15:34.650",
"references": [
{
"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n39k-isis-dos-JhJA8Rfx",
"source": "psirt@cisco.com"
}
],
"vulnStatus": "Deferred",
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"source": "psirt@cisco.com",
"description": [
{
"lang": "en",
"value": "CWE-733"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) feature of Cisco NX-OS Software for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, adjacent attacker to cause the IS-IS process to unexpectedly restart, which could cause an affected device to reload.\r\n\r\nThis vulnerability is due to insufficient input validation when parsing an ingress IS-IS packet. An attacker could exploit this vulnerability by sending a crafted IS-IS packet to an affected device. A successful exploit could allow the attacker to cause the unexpected restart of the IS-IS process, which could cause the affected device to reload, resulting in a denial of service (DoS) condition.\r\nNote: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device."
},
{
"lang": "es",
"value": "Una vulnerabilidad en la función de sistema intermedio a sistema intermedio (IS-IS) del software Cisco NX-OS para los switches Cisco Nexus de las series 3000 y 9000 en modo NX-OS independiente podría permitir que un atacante adyacente no autenticado provoque el reinicio inesperado del proceso IS-IS, lo que podría provocar la recarga del dispositivo afectado. Esta vulnerabilidad se debe a una validación de entrada insuficiente al analizar un paquete IS-IS de entrada. Un atacante podría explotar esta vulnerabilidad enviando un paquete IS-IS manipulado a un dispositivo afectado. Una explotación exitosa podría permitir al atacante provocar el reinicio inesperado del proceso IS-IS, lo que podría provocar la recarga del dispositivo afectado y provocar una denegación de servicio (DoS). Nota: El protocolo IS-IS es un protocolo de enrutamiento. Para explotar esta vulnerabilidad, un atacante debe estar adyacente a la capa 2 del dispositivo afectado."
}
],
"lastModified": "2026-06-17T08:41:10.377",
"sourceIdentifier": "psirt@cisco.com"
}