Servers might run okay out of the box, but before you put it in production, there are 10 steps you need to make sure it's configured securely. The details of these steps may vary from distribution to distribution, but conceptually they apply to any flavor of Linux. By checking these steps off on new servers, you can ensure that they have at least basic protection against the most common attacks.
• Common oversights that compromise the security of servers
• 10 practical steps you can take now to make it far more difficult for malicious hackers to breach your server