FKIE_CVE-2023-4346

Vulnerability from fkie_nvd - Published: 2023-08-29 20:15 - Updated: 2026-07-16 05:16
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
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.
References
ics-cert@hq.dhs.govhttps://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01Third Party Advisory, US Government Resource
af854a3a-2127-422b-91ae-364da2661108https://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01Third Party Advisory, US Government Resource
134c704f-9b21-4f2e-91b3-4a467353bcc0https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4346US Government Resource
Impacted products
Vendor Product Version
knx connection_authorization -
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "KNX Protocol Connection Authorization Option 1",
          "vendor": "KNX Association",
          "versions": [
            {
              "status": "affected",
              "version": "0"
            }
          ]
        }
      ],
      "source": "ics-cert@hq.dhs.gov"
    }
  ],
  "cisaActionDue": "2026-07-29",
  "cisaExploitAdd": "2026-07-15",
  "cisaRequiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA\u2019s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA\u2019s \u201cForensics Triage Requirements\u201d (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\u0027s 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",
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:knx:connection_authorization:-:*:*:*:*:*:*:*",
              "matchCriteriaId": "F328E1CB-8666-4D06-B2BC-9532454AF906",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "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 autorizaci\u00f3n de conexi\u00f3n KNX y admiten la Opci\u00f3n 1 son, seg\u00fan la implementaci\u00f3n, vulnerables a ser bloqueados y los usuarios no pueden restablecerlos para obtener acceso al dispositivo. La funci\u00f3n de clave BCU en los dispositivos se puede usar para crear una contrase\u00f1a para el dispositivo, pero esta contrase\u00f1a a menudo no se puede restablecer sin ingresar la contrase\u00f1a actual. Si el dispositivo est\u00e1 configurado para interactuar con una red, un atacante con acceso a esa red podr\u00eda interactuar con la instalaci\u00f3n KNX, purgar todos los dispositivos sin opciones de seguridad adicionales habilitadas y configurar una clave BCU, bloqueando el dispositivo. Incluso si un dispositivo no est\u00e1 conectado a una red, un atacante con acceso f\u00edsico al dispositivo tambi\u00e9n podr\u00eda aprovechar esta vulnerabilidad de la misma manera.\n"
    }
  ],
  "id": "CVE-2023-4346",
  "lastModified": "2026-07-16T05:16:16.603",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "ics-cert@hq.dhs.gov",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2023-4346",
          "options": [
            {
              "exploitation": "active"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-15T00:00:00+00:00",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2023-08-29T20:15:10.300",
  "references": [
    {
      "source": "ics-cert@hq.dhs.gov",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory",
        "US Government Resource"
      ],
      "url": "https://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "US Government Resource"
      ],
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4346"
    }
  ],
  "sourceIdentifier": "ics-cert@hq.dhs.gov",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-645"
        }
      ],
      "source": "ics-cert@hq.dhs.gov",
      "type": "Secondary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.