[K12OSN] server hardening (disable list)

Rob Owens rob.owens at biochemfluidics.com
Thu Sep 18 19:05:00 UTC 2008

I think you should first give those kids extra credit for being
resourceful, then give them extra credit every time they report a new
"exploit" for you to fix.  Turn it into a challenge for them and keep
them on the white hat side of things.


Robert Arkiletian wrote:
> Some of my students (with previous Linux experience) discovered these programs
> mail
> write
> wall
> in addition they were attempting to guess passwords and even share passwords.
> su
> sudo
> I changed permissions on all of the above to only allow root or myself access.
> I teach command line so they need to have access to a shell terminal.
> But having students start a chatting frenzy or fill logs with mail is
> annoying.
> In addition if you have generic accounts like comp1, comp2, comp3 they
> can change the default password.
> So I had to disable
> passwd
> for the generic accounts.
> In addition I have disabled cron for everyone except root and myself.
> Disable atd. Also disabled nohup. In addtion I have a script that logs
> everyone off (kills all user processes) at the end of the school day.
> Also secured sshd.
> I was hoping others on the this list could contribute
> ideas/experiences of what should/could be disabled.

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