CVE-2023-4346

Analyzed
Published: 29 Aug 2023, 19:38
Last modified:16 Jul 2026, 03:55

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
v3.1 (cve.org)
EPSS Score
0.91% LOW
1% probability +0.86%
KEV
Listed
CISA
1 listing
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

29 Aug 2023, 19:38
Published
Vulnerability first disclosed
15 Jul 2026, 00:00
Added to CISA KEV
KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability
16 Jul 2026, 03:55
Last Modified
Vulnerability information updated
29 Jul 2026, 00:00
CISA Remediation Due
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.

Description

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 Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.91%• Percentile: 57%

Techniques & Countermeasures

  • CWE-645•Overly Restrictive Account Lockout Mechanism

    The product contains an account lockout protection mechanism, but the mechanism is too restrictive and can be triggered too easily, which allows attackers to deny service to legitimate users by causing their accounts to be locked out.

Affected Systems

  • knx association•knx protocol connection authorization option 1

    All versions

  • knx•connection_authorization

    na

References (2)