Linux is, by design, a very secure operating system, but so what? You can have the best security system in the world on your house, but if you leave your front-door open anyone can still walk in. Even people who know better, like Linux kernel developers, blow it sometimes. That’s what happened to the Linux Foundation’s constellation of sites. Multiple important Linux sites were down for weeks and as of October 3rd, kernel.org is still down. This doesn’t have to happen to you. Here are a few simple suggestions from me, and some more advanced ones from Greg Kroah-Hartman, one of Linux’s lead developers.
First, here are some rules that everyone should know. Number one with a bullet is security expert Bruce Schneier’s mantra, “Security is a process, not a product.” I don’t care that your server was Fort Knox, two weeks ago, if you haven’t updated your system with the latest security patches, checked to make sure your users haven’t started running a porn Web server, and looked over your network logs to see if someone or something isn’t up to mischief then you can’t trust your system today.
In addition, as Kroah-Hartman wrote, “it is imperative that nobody falls victim to the belief that it cannot happen to them. We all need to check our systems for intrusions.” And, I might add, we need to keep doing it all the time.