The COVIDSafe (Australia) app 1.0 and 1.1 for iOS allows a remote attacker to crash the app, and consequently interfere with COVID-19 contact tracing, via a Bluetooth advertisement containing manufacturer data that is too short. This occurs because of an erroneous OpenTrace manuData.subdata call. The ABTraceTogether (Alberta), ProteGO (Poland), and TraceTogether (Singapore) apps were also affected.