Secure Shell, or ssh, quickly became the replacement for telnet, rlogin, and rsh once system and network administrators realized how easy it was to capture credentials and modify traffic in flight. It’s the stuff out of movies. An administrator is logging into a system with an elevated account (such as root) while a bad guy is snooping all of the traffic and displaying the stream on his screen. He’s got all the credentials and can see everything that administrator is doing. Or worse, he’s sitting in between the administrator and his equipment and modifying the keystrokes from the administrator before forwarding them to the device.
Cue the dramatic music.
After its release over twenty years ago, it has seen near ubiquitous deployment and multiple versions of the protocol. Configured properly, it’s a quite secure way to reach across networks to use or administer computing devices. Configured poorly, it’s still an improvement over telnet, but will foster a false sense of safety in its use.
A post from last year by stribika gives great advice for boosting the overall security of your Secure Shell installations, including how you manage your own personal identity using SSH Keys. After dealing with some machines for more than 10 years, I realized that I needed to make a few changes—mostly on the host side. Give this article a read to learn how you can make your Secure Shell infrastructure as secure as possible!