Hardening Linux Web Servers
Security is a process, not a result. It is a process which is difficult to adopt under normal conditions; the problem is compounded when it spans several job descriptions. All the system level security in the world is rendered useless by insecure web-applications. The converse is also true—programming best practices, such as always verifying user input, are useless when the code is running on a server which hasn’t been properly hardened. Securing forward facing GNU/Linux web servers can seem like a daunting task, but it can be made much easier by breaking the process into manageable portions.
Link here.
