This, or the story is false, purposely or not.
If we're talking about being able to make changes at the OS level, surely those should be relatively easy to spot?
If we're talking about copying packets, wouldn't that be useless under most circumstances?
If we're talking about doing whatever on a mass scale, surely most of the data would be junk and a huge and very clever backend would be needed to sift out the useful elements?
Presumably none of this is impossible, but I haven't yet seen a good description of how it's all supposed to fit together.
That requires more than just access to the network, but it is rather simple.
With just access to the network, perhaps one could do spoofed DNS responses that are never seen on the network? A very simple '1% of the time, set the gmail.com A record to the chinese gmail IP' might be enough.
One could create mayhem by sending false ARP or DHCP responses, but that is only mayhem. Perhaps if it is externally triggerable it is useful offensively as DoS.
If you are blocking outbound, I could still this going unnoticed if you're not actively reviewing denials.
But, if you are properly watching dns lookups from OOB and it's anything other than necessary services (ntp, ldap, syslog), then this would get picked up pretty quickly.
Most places might be blocking this type of activity by default. For most of our security audits, it's just assumed that the SM IPMI or Dell idrac is vulnerable to one exploit or another. We mitigate that by controlling the traffic. I feel this is common practice in most places that understand vlans and firewalls.
However, while blocking is easy, being aware of something like this is on another level altogether. Unicorn jumping over a rainbow level rare. You really have to be logging outbound attempts and dns lookups. Where I work, there is a full security team and they are at an insane level where they log the allowed traffic. One told me that the allowed traffic is more interesting than the denied traffic. Denied just tells them what we anticipated, while active helps them establish a pattern and look for deviations.
Quite, especially in small networks and inline ilos, entirely possible that people plug the ilo (ipmi etc) to a more open network. Sure, nothing in, but no block on stuff going out.