Of course, the other way to do this is to learn how to use the BSD derived ipfw tool directly, and dispense with managing the firewall in the GUI. Changing the permissions back and rebooting will reactivate the built-in firewall.
defaults write /Library/Preferences/ firewall -dict-add 'Apple Remote Desktop' 'editable0enable1port5900-59023283'The only problem I encountered with this method is that the defaults command tends to change the ownership of the file from -rw-r-r- root admin, which also disables the firewall. Below is an example of the command I used in this case to add the ARD exceptions. In an effort to automate the addition of a firewall exception for the latest version of Apple Remote Desktop, I found a way to use the defaults write command in the Terminal to create the rule without using the System Preferences panel.
