Aruba is using tinyproxy behind the scenes to parse external captive login page and look for success text.
From my experiments, it seems that tinyproxy connection timeout is set to 5 seconds by default which may not be enough in some cases (it's not enough in my case). After 5 seconds, the connection is abruptly closed and CNA doesn't understand what just happened.
I'm trying to find a way to increase the timeout, so far no luck.
Any ideas?