TNS Listener Poison Attack...externally or internally ?

Question

Hello all,
with regrads to the below thread which mostly talks about Oracle Security Alert for CVE-2012-1675 "TNS Listener Poison Attack"....i just wanted to find out if this effect DB that are externally or internally....meaning 95% of our DB are in network(internally) behind our firewall....and rest of the 5% are outside our firewall facing the world wide web....so does this apply to both of just one ?
Oracle TNS Poison vulnerability

Answer 1

user097815 wrote:
with regrads to the below thread which mostly talks about Oracle Security Alert for CVE-2012-1675 "TNS Listener Poison Attack"....i just wanted to find out if this effect DB that are externally or internally....meaning 95% of our DB are in network(internally) behind our firewall....and rest of the 5% are outside our firewall facing the world wide web....so does this apply to both of just one ?The attack is on the Listener itself - so if you want to prevent this attack, you need to secure that Listener, irrespective of its location.
IMO, mandatory if you expose your Listener to an unsecured or public network (e.g. internet).
As for Listeners running on your internal network - if this attack is used, securing your Listeners mean very little IMO. Because your internal network already needs to be compromised in order for the attack to occur. Which means you have far more serious problems then someone attacking your Listeners.