I've not seen any errors on any of the machines running bitdefender on our network so this question is potential unnecessary but I would like to know of the requirements for access to catch-nimbus.bitdefender.net.
The question stems from the fact that cloudflare's malware DNS resolver is blocking this address (returns 0.0.0.0)
Are there any concerns with the filtering of access to this service? If so, what is the service used for?