hardening a debian squeeze server

rbees · 03-07-2012, 07:47 PM

is it safe, meaning the system will function correctly, to remove the marked users/groups

bin
sys
sync **delete**
man
uucp
proxy **delete**
www-data **delete**
backup
list **delete**
gnats **delete**
nobody
libuuid
Debian-exim **delete**
statd
messagebus

The system is a rebuild for an external firewall/dns(cacheing) bastion host. A distro-upgrade of the existing has caused problems ;(

Anyway what do you think? Still checking google.

Thanks.

rbees · 03-07-2012, 08:49 PM

there is also this list of groups that I would like to pare down

bin
sys
adm
tty
disk **delete**
man
proxy **delete**
kmem
dip
www-data **delete**
backup
operator **delete**
list
src **delete**
gnats
shadow
utmp
video **delete**
sasl
plugdev
users
nogroup **delete**
libuuid
crontab
Debian-exim
mlocate
ssh
bind
messagebus
utempter

Thanks

elfenlied · 03-07-2012, 09:00 PM

As long as any services / daemons that may use those accounts aren't required I don't see why not. Although as long as an account doesn't have a password and can't login it shouldnt cause you any harm.

rbees · 03-08-2012, 10:14 PM

ended up putting the users I deleted back into the system

Instead of deleteing run "passwd -l <username>", and set their login shell to /bin/nologin or /bin/false
on those users you want to disable