Cant access firewall in system preferences; firewall tab is greyed out I have tried multiple things to rememdy this issue. I have tried enabling and logging in as root, tried to clone the system preferences app and accessing security and privacy from the view menu and nothing seems to work. I have repaired permissions from disk utility, repaired permissions through terminal at utility repair and still nothing. I will say that there was a previous user at my machine which I went through the best approach I could find by saving the previous home folder and creating another. My new user is set to administrator also. I am open to any suggestions here as I am fresh out of ideas.

I also made sure to authenticate via the lock icon in system preferences pane.

Im running:
-3.4ghz i7 imac
-16g ram
-osx mavericks 10.9.5
-local network

Update:
just tried running this in terminal and restarting… also to no avail
sudo rm /Library/Preferences/com.apple.alf.plist

Update:
tried toggling socketfilterfw off and then on through terminal but both times terminal output that the firewall was already in the state I was attempting to set it to.
still no solution…

Update:
Im now gearing to wipe and reinstall my os drive. I have run out of things to try and assume that it's a convoluted permissions issue. If anyone has any last-ditch ideas, I'm all ears. Thanks for everyone's help.

Final Update:
I wiped and reinstalled… never got a solution to this one.
My first assumption is that you have a app like Anti Virus that took over the control of your Firewall.

Here is a article on using the Terminal commands with Firewall.

It is for Lion, but I assume they still work with Mavericks.

For example to start it: 

/usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate on


Give it a try.