We are running z/OS 1.6. We noticed that a Portscan including port zero repeatedly crashes the IP Stack! Unfortunately I was not able to find any hint in the known knowledgebases. Is this a known vulnerability ?
I did my own search and could not find anything, but that doesn't mean it is not a known problem. Either way, I suggest opening a PMR with IBM Communications Server TCP/IP support. If it is a known problem, they will point you to a fix. If it is not, they will direct you on what type of traces, dumps, or other documentation they need to diagnose and fix the problem. The good news is that since the problem is repeatable, you can get IBM the documentation they will need. Hopefully you can do this on a test LPAR.
This was first published in June 2006