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CVE-2023-4346

KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism

7.5 HIGHActively exploited (CISA KEV)EPSS 1.29%
  1. Published29 Aug 2023
  2. Added to CISA KEV15 Jul 2026
  3. Remediation due29 Jul 2026
Actively exploited (CISA KEV)

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.

Added to KEV: 15 Jul 2026Federal remediation due: 29 Jul 2026

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 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Knx Connection Authorizationall versions

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

Frequently asked

Is CVE-2023-4346 being actively exploited?

Yes. CVE-2023-4346 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 15 Jul 2026.

How severe is CVE-2023-4346?

CVE-2023-4346 has a CVSS 3.1 base score of 7.5, rated high. EPSS estimates a 1.29% probability of exploitation.

Which products are affected by CVE-2023-4346?

Affected products include Knx Connection Authorization.

How do I fix CVE-2023-4346?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2023-4346 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.