firewall – Interception of network traffic with a hub

In theory, yes. I did it for over a year some time ago. Prepare for the possibility that this affects your overall throughput, especially if you have a lot of traffic and approach the maximum of your firewall's interface.

Another caveat: at a conference where a team was going to demonstrate this with the help of a Linksys hub, they discovered that Linksys customized some of their switches as hubs. It was more than 5 years ago, but I wanted to warn you to avoid any potential frustration.