CVE-2023-4346: KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability
Affects KNX Association KNX Protocol Connection Authorization Option 1Source CISA KEV
No CVSS score published yet
- Exploitation
Actively exploited – in CISA KEV since 07/15/2026
- KEV deadline
- 07/29/2026
- EPSS
- 1.3% chance of exploitation in 30 days – higher than 70% of CVEs
What to do
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.
- cisa.gov/news-events/ics-advisories/icsa-23-236-01 (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2023-4346 (opens in a new tab)
Description
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.
Weaknesses
References
- cisa.gov/news-events/ics-advisories/icsa-23-236-01 (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2023-4346 (opens in a new tab)
- cisa.gov/known-exploited-vulnerabilities-catalog?search=CVE-2023-4346 (opens in a new tab)