This question stems from my other question, sorry if it is too similar. Now I would like to know what mechanism is used to sandbox network processes and (if relevant) individual programs, if at all?
Obviously, if the local machine is comporomised and someone has a screensharing program or keylogger installed, all bets are off. I also now that the processor is sandboxed into protection rings, and network information is seperated at some layer of the protocol stack, probably somewhere in the IP/TCP/Session/Application layers along with their unique port numbers used for identification. (Additional clarification on my two previous vague points about rings and layers with relation to my question would be informative).
Scenario: You are doing banking on your web browser with outgoing Port 80 and random uncommon incoming ports. I open a legitimate local Java program which accesses information on the internet on a different port. What kind of crosstalk may be possible? (If language matters, i.e. something other than Java, please explain).
As in my other question, I am not talking about actively malicous software. More like, what is possible for the Java program or Web browser to detect about each other in a normal environment. Obviously, it would be considered malicious for either program to obtain and send information about the network process without the user's permission... but how far out can each process reach?
Analogy For Asking: Original hubs worked by transmitting information on all ports to all clients which posed a significant LAN concern. All a NIC adapter had to do to listen was to not discard frames not destined for itself. However, this was considered to be normal operation. Is there some reason I should not run banking and other external Java programs simultaneously? If the machine is comporomised completely, then obviously this makes no difference. But I am asking... well I hope you know by now.
CLARIFICATION: My question generally deals with programs which are creating sockets and such. Obviously, all of these programs share a common foundation, the CPU and memory, but programs that do not open ports, or are blocked by the software firewall by default, do not concern me as much. Or should they?