CVE-2023-4346
Knx Connection Authorization
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2023-4346 is a high-severity Overly Restrictive Account Lockout Mechanism (CWE-645) vulnerability in Knx Connection Authorization. Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 44% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-54211
Vulnerability Data
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…
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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.
- CWE(s)
- KEV Date Added
- 15 July 2026
Related Threats
Likely ATT&CK TechniquesAI
Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Credential management policies directly govern lockout thresholds and reset procedures.
Authentication policies include lockout parameters that must not be overly restrictive.
Authorization policy definition and review encompass account lockout rules and exceptions.
Monitoring can detect resulting lockouts but does not prevent an overly restrictive mechanism.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Access control policy should define lockout thresholds and recovery procedures to avoid overly restrictive denial-of-service.
Authentication information management includes setting lockout parameters that balance security against accidental lockouts.
Access rights administration must include procedures for unlocking accounts and reviewing lockout events.
Secure authentication mechanisms directly specify lockout thresholds, unlock processes, and monitoring to prevent abuse.
Logging of authentication events enables detection of lockout abuse but does not prevent the weakness itself.
Monitoring can detect excessive lockouts but does not define or enforce appropriate lockout parameters.