@mr_bobo:
I do have a browser I only use to log on to the Web GUI to check my logs, and always log out and close the browser right after I'm done, but have on occasion opened a new window to an online tools site I use to resolve IP#'s that appear in the firewall logs while logged in.
I knew there was a reason I felt uneasy when I didn't open a separate browser to check those IP#'s. ::)
You're reasonably safe with us if you stay up to date. Other web-managed products, unfortunately not so much. There are a number of commercial security-related products with serious unpatched CSRF and XSS issues. It would be safest to assume every web-managed device has CSRF and XSS issues and act accordingly, primarily use a different browser than one you use for any general Internet usage. These recommendations from 2008 still stand true today.
http://blog.pfsense.org/?p=232