HIGH: CVE-2023-4346 actively exploited — knx connection authorization

CVE: CVE-2023-4346

CVSS: 7.5 (3.1) — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: HIGH

Status: ✅ Confirmed exploited in the wild (CISA KEV)

Affected

• knx connection authorization

Summary

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.

Verified Sources

• NVD entry
• GitHub Advisory
• MITRE
• CISA Known Exploited Vulnerabilities Catalog

References

• https://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01
• https://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4346

_Validated by the Lyrie Threat Intelligence Pipeline — 3 independent sources confirmed before publication. No speculation._