In the Firewall page there is a list of IP's that have been blacklisted or whitelisted. There is a possibility to select an IP with a checkbox. If you select only one IP from the list, the Actions menu item does not appear and thus you don't have an easy possibility to for example blacklist IP permanently.

If you elect two IP's, the Actions menu item appears. However when you try to perform permanent blacklist for multiple IP addresses, it only adds it for one selected IP.