CoD4 CPSP is a small script designed to protect your CoD4 server from those retards who think flooding your server with fake players is funny.
You need root access to your server as well as a Python interpreter. Optional but you should use tmux to run the script in, you can use screen but I do prefer tmux. You may edit the ban line to your liking but it's configured for csf.
The script works by polling the server for a "status" every n amount of seconds, it then counts how many players are in CNCT status and firewalls the IP if the count of concurrent connecitons is above n amount.
If your RCON is floodable, then this little workaround will NOT work as most fake player spam bots come with an RCON flooder.