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.

KNX ETS6 through 6.0.0 uses the hard-coded password ETS5Password, with a salt value of Ivan Medvedev, allowing local users to read project information, a similar issue to CVE-2021-36799. NOTE: The vendor disputes this because it is not the responsibility of the ETS to securely store cryptographic key material when it is not being exported

KNX ETS5 through 5.7.6 uses the hard-coded password ETS5Password, with a salt value of Ivan Medvedev, allowing local users to read project information. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

Buffer overflow in the Group messages monitor (Falcon) in KNX ETS 4.1.5 (Build 3246) allows remote attackers to execute arbitrary code via a crafted KNXnet/IP UDP packet.