Creating a secure Debian server
My favourite linux distro is Debian. Ubuntu Server is also great, but in my case generally I only need a LAMP server (Linux + Apache + MySQL + PHP), without big network responsabilities (mainly on intranets implementations). And, finally, Ubuntu is Debain based. Because this, I choose the lighter option, Debian. For graphic interface, I prefer LXDE, one of the lightest actually.
If it was only install and bring it up, would be great. Otherwise, when a server is exposed on Web, it becames to be target of many malicious bots, which searches security fails over all internet , IP by IP, almost port by port.
Taking a look at /var/log/auth.log of a open web server, we can identify a lot of connection tries with common usernames, like admin, test, guest, user and so on.
If your Debian (or Ubuntu) server is already up, I guess the most interesting chapters are:
- Chapter 4 - After installing
- Security updates
- GRUB (or LILO) configuration
- Restrict terminal access
- Configuring partition mount options
- Limit resources
- Restrict FTP
- Auditing users
- System snapshots
- Chapter 5 - Securing services running on your system
- Improving SSH and FTP security
- Improving Apache security
- Security in mail services
- Turnig off users home publishing on Apache
- Firewall implementation