CVE-2023-4346
KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability
This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run KNX Protocol Connection Authorization Option 1, fix it now.
CISA required action: 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.
US federal civilian agencies must remediate by Jul 29, 2026.
Patch status
No official fix confirmed yet
Until a fix ships, follow the vendor's mitigations and CISA's required action, limit exposure of affected systems, and watch this record for a patch.
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.
Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.
Affected products
| Product | Vendor | Source |
|---|---|---|
| KNX Protocol Connection Authorization Option 1 | KNX Association | KEV |
Sources: KEV = CISA Known Exploited Vulnerabilities catalog. Version details have not been published yet.
Intelligence timeline
Developments from the last 30 days, newest first.
No developments recorded for CVE-2023-4346 in the last 30 days.
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Coverage
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