Please boost for visibility! If you are running a #Mikrotik router or switch, upgrade it now. Right now. The fixed releases are 7.23.4 (long-term), 7.24.2 (stable) and 6.49.21. If you are running a version less than that, there are multiple entrypoints for a complete unauthenticated remote code authentication.
This is as bad as it gets, upgrade and reboot now. Yes, you'll have an outage for a few minutes, but it's better than the alternative.