There are quite a few threads on server security. However I haven't seen any discussions or resources on protection against your own users. For those who are hosting web sites on dedicated servers - what precautions did you take to protect your server (as well as hosting clients) from your customers? For instance, stop customers from snooping on other accounts or stop access to admin functions. I know these examples are rather trivial. I hope to gain any insight you want to share. :)

Disallow telnet or any kind of "shell" access. Shell access is the number one security risk. I found the biggest problem with permitting shell access, is that there is always someone who sets up a friggin IRC bot, gets in a flame ware on IRC, and generates a denial of service attack. Also, this same person is liable to see what he can change in other peoples directories just to "mess with them", just to "prove his provider is rinky-dink organization", or because he's lost.

Chroot is your friend on unix. I generally set up ftp access so that they are fully chrooted in their own directory and can't roam around the system. This can also be applied to shell access, however, their are several cracks available for most operating systems that can bypass the chroot environment in a shell session.

IIS is more limited in it's capabilities to set up a chroot environment than unix. Unix was designed to be a multi-user environment from the get-go.

There are a few good system administrator books out there that can give you a better outline of the capabilties of the particular OS you are using.

Is there a way to "lock" a program to run based on the name ? (that just hit me )

like prevent anythig that's named "eggdrop" to run ? .. of course people could allways change the name .. but still :)

you could have a cronjob that runs around changing eggdrop to ownship by root and group root with readonly permission by root (ie, chmod 400). On some OS/shell combos they wont be able to delete the file and wont be able to run it. But, yes, they could always name it something else.

You could create a program in the first directory of the directory path and that would confuse them for a while. But that has limited influence.

Since eggdrop and other IRC bots rely on cron for many of their task. You could limit access to cron. That might backfire if they IRCer gets annoyed and decides to DOS you (which isn't as unusual as you think).

How did I come to hate IRC service so much? I have run datacenter networks and systems for several years. The most chronic problems were the result of colocated server owner not watching (or caring, or knowing to watch) what their users were doing. It not only causes a problem on the server. It can cause a performance and security problem on the entire network. IRC certainly has uses, but should be ran on network dedicated to IRC service (their are several) so that flame wars can have limited impact on our servers and services.

I agree

It's sad but over 1/2 of all server problems we have have been caused by users installing .. eggdrop (and what comes after)