Earlier quoted context omitted.
Rubygems for everybody! Or arbitrary docker containers. My current deployments allow outbound SMTP only. All software packages (rpm or whatever) get pushed in via rsync from the outside, or are built in an adjacent lab behind the firewalls and pushed across.
It may affect the very source box you are using for package downloads. I bet it is allowed to go outside unrestricted. Funny you mentioned Docker, it is a security nightmare in itself.
Oh yeah - docker. I thought this one was pretty funny:
https://threatpost.com/malicious-docker-containers-earn-cryp...