CVE-2023-4346
KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability
CVSS
7.5
Alto
EPSS
1.3%
p70
KEV
SÍ
15 jul 2026
Exploit Today
71
0-100
Publicado: 29 ago 2023 · Última mod.: 16 jul 2026 · CWE-645
Producto
KNX Association / KNX Protocol Connection Authorization Option 1
Vulnerabilidad
KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability
Añadido a KEV
15 jul 2026
Remediar antes de
29 jul 2026
Uso conocido en ransomware
No
Descripción resumida
KNX Association KNX Protocol Connection Authorization Option 1 contains an overly restrictive account lockout mechanism vulnerability that could allow an attacker to purge all devices without additional security options enabled and set a BCU key to lock the device.
Acción requerida
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.
Notas
https://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2023-4346
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.