CPF requires Firefox be allowed as Server?

Why do I have to allow Firefox to be a server to access the internet? Is this normal? I am trying CPF on my laptop in preparation of setting up a new desktop that is on its way. I have been using Kerio up to now, but I have heard so many good things about CPF that I wanted to try it. I have 6 or 8 computers that I look after (friends and relatives) and if CPF is stable and easy to use, I will switch them over.

Thanks for any help you can give.


Hi, and welcome to the forums.

I use FireFox and i get the same thing - FireFox acting as a server. As far as i can tell this is normal.

Version, I presume…? (:WIN)

Yes, this is normal. You will notice in your connections that it’s connected locally; localhost (, and/or your LAN (probably the Gateway address, which you can find by going to Start/Run, type “cmd” and at the prompt, “ipconfig /all”).

At any rate, it’s an internal thing only; doesn’t mean your computer is being opened up to the internet by Firefox pretending it’s a physical server. You can Allow with Remember, and not worry about it.


Is this a vulnerability? Does this leave a hole in my security?


Not at all. It’s all internal and/or local.

Your “localhost” (127.0.0.x) is basically another way of defining one aspect of your computer; it’s used by programs communicating back and forth with each other, and with the OS. Perfectly normal.

The gateway connections (probably 192.0.0.x or 10.0.0.x, if you’re connecting to the internet through a server or router) are there to help assign your internal IP address (for the network, not the internet), and other things of that nature.

If you look at Activity/Connections in CPF, you will see what’s connected (what applications) whether the traffic is In or Out, and what the Source and Destination points are. If the traffic is Outbound, the Source is you; Destination is where it’s going. If the traffic is Inbound, the Source is where it’s coming from; Destination is you. Thus you can see if it’s internal or not.

But the thing of “Firefox acting as a server” is not a cause for concern.