Tips for Securing a LAMP Server
On a Linux based server, what are some of the best practices for securing PHP?
What functions should be disabled (ex. exec, exec_shell, system)?
mod_php is not a solution because all PHP processes run with the same UID and access rights.
I use suPHP for a shared server. That way all users have their own system accounts and every PHP process is run with their own UID. --> Pro: users have restricted access and are isolated from each other. Con: less performance because it is basically a CGI model.
Stuart Herbert had a blog series about on this and other PHP setup solutions.