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.
do firstApply 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.
Can a WAF block it? No. The attack requires network access to the KNX installation using the KNX protocol, which is not HTTP-based, so a web application firewall cannot filter or block the malicious requests.
Also consider: patch
Based on an AI reading of the CVE description, and no vendor rule found yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Is CVE-2023-4346 being exploited?
Yes. CVE-2023-4346 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2023-4346?
CVE-2023-4346 is rated High with a CVSS score of 7.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2023-4346?
Not known from our data. No patch reference has been recorded for CVE-2023-4346, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2023-4346 affect?
CVE-2023-4346 affects knx:connection_authorization. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
cisa ssvc
- exploitation
- active
- automatable
- yes
- technical impact
- partial
Assessed by CISA 15 Jul 2026 (SSVC 2.0.3).
timeline
- 29 Aug 2023Published
- 15 Jul 2026Added to CISA KEV (exploited in the wild) · 1,050 days (about 3 years) later
- 15 Jul 2026CISA SSVC assessment: exploitation active · same day later
- 16 Jul 2026CVE record last updated · 1 day later
- 29 Jul 2026CISA remediation due date (US federal agencies) · 13 days later
- 2 Nov 2026Analysed by vulneraibility.com · 97 days (about 3 months) later
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.