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CVE-2023-4346

Estado: AnalizadaAlta (7.5)⚠ Explotación activa

KNX devices that use KNX Connection Authorization and support Option 1 are, depending on the implementation, vulnerable to being locked and users being unable to reset them to gain access to the device. The BCU key feature on the devices can be used to create a password for the device, but this password can often not be reset without entering the current password. If the device is configured to interface with a network, an attacker with access to that network could interface with the KNX installation, purge all devices without additional security options enabled, and set a BCU key, locking the device. Even if a device is not connected to a network, an attacker with physical access to the device could also exploit this vulnerability in the same way.

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

🎯 Técnicas ATT&CK

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

AV:N sin autenticación permite acceso remoto a dispositivos KNX via red; la capacidad de bloquear dispositivos estableciendo BCU key constituye denegación de servicio operacional.

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

Filter Network TrafficVulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkApplication Isolation and Sandboxing

Tecnologías afectadas (1)

KNX — Connection Authorization

CWE

Referencias

JSON original (NVD)

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{
  "id": "CVE-2023-4346",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2023-4346",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "active"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
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          ],
          "version": "2.0.3",
          "timestamp": "2026-07-15T00:00:00+00:00"
        }
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    "cvssMetricV31": [
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        "type": "Secondary",
        "source": "ics-cert@hq.dhs.gov",
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          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
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          "userInteraction": "NONE",
          "attackComplexity": "LOW",
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          "confidentialityImpact": "NONE"
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  "affected": [
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          "product": "KNX Protocol Connection Authorization Option 1",
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  "published": "2023-08-29T20:15:10.300",
  "references": [
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      "tags": [
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      "source": "ics-cert@hq.dhs.gov"
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      "tags": [
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
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      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4346",
      "tags": [
        "US Government Resource"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
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  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "ics-cert@hq.dhs.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-645"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "\nKNX devices that use KNX Connection Authorization and support Option 1 are, depending on the implementation, vulnerable to being locked and users being unable to reset them to gain access to the device. The BCU key feature on the devices can be used to create a password for the device, but this password can often not be reset without entering the current password. If the device is configured to interface with a network, an attacker with access to that network could interface with the KNX installation, purge all devices without additional security options enabled, and set a BCU key, locking the device. Even if a device is not connected to a network, an attacker with physical access to the device could also exploit this vulnerability in the same way. \n\n"
    },
    {
      "lang": "es",
      "value": "Los dispositivos KNX que utilizan la autorización de conexión KNX y admiten la Opción 1 son, según la implementación, vulnerables a ser bloqueados y los usuarios no pueden restablecerlos para obtener acceso al dispositivo. La función de clave BCU en los dispositivos se puede usar para crear una contraseña para el dispositivo, pero esta contraseña a menudo no se puede restablecer sin ingresar la contraseña actual. Si el dispositivo está configurado para interactuar con una red, un atacante con acceso a esa red podría interactuar con la instalación KNX, purgar todos los dispositivos sin opciones de seguridad adicionales habilitadas y configurar una clave BCU, bloqueando el dispositivo. Incluso si un dispositivo no está conectado a una red, un atacante con acceso físico al dispositivo también podría aprovechar esta vulnerabilidad de la misma manera.\n"
    }
  ],
  "lastModified": "2026-07-16T05:16:16.603",
  "cisaActionDue": "2026-07-29",
  "cisaExploitAdd": "2026-07-15",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
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          "operator": "OR"
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  "sourceIdentifier": "ics-cert@hq.dhs.gov",
  "cisaRequiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.",
  "cisaVulnerabilityName": "KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability"
}