In Portable Firefox for Windows, I looked at the options where it lists SSL certificates. I know that Windows stores SSL certificates in its own store. Does Firefox use these certificates? I am curious because if I use a computer at a store or business, they could have their own certificates installed on the computers. Does Firefox automatically load these certificates? Because the traffic goes through their network, could they use this to forge SSL?
If you are using someone else's computer, they can already intercept what you are doing (for example, they could have a keylogger that would capture sensitive information that you enter). It doesn't matter whether or not they can impersonate a site; you should not assume that anything you type in is secure from them.