A vulnerability has been identified in Desigo DXR2 (All versions < V01.21.142.5-22), Desigo PXC3 (All versions < V01.21.142.4-18), Desigo PXC4 (All versions < V02.20.142.10-10884), Desigo PXC5 (All versions < V02.20.142.10-10884). When the controller receives a specific BACnet protocol packet, an exception causes the BACnet communication function to go into a “out of work” state and could result in the controller going into a “factory reset” state.
https://cert-portal.siemens.com/productcert/pdf/ssa-662649.pdf