Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Hiding Software Versions - A Step Forward to a Secure Server
Most of you may not notice, or may not care, about the software versions that get revealed by the running services on your server. By default almost all services reveal some information to the clients that use them. Among this information is the version of the software that is being run. It has always been best practice, not to reveal more than it is needed. Why reveal the version of the service when nobody needs to know it? By letting these details be seen, you don't get anything else, but an extra chance for crackers to break into your server.
Let's suppose that you have an old software running, and it's configured to show it's version. For a cracker who scans the internet periodically it will be very easy to hack into your server if he already has some knowledge about your server. You will help him narrow his attempts only to those related to your software version.
So, by hiding the software version you make life harder for hackers/crackers. Of course you should, at all times, keep your system up to date, but in case you forget or something happens and you are unable to do so, why not take extra care and give as little information as possible to the outside world.
I will now show you how to change this default behavior for some popular software on Ubuntu 8.04.1 Server.
Read the full article at: