[CentOS] Unknown rootkit causes compromised servers

Fri Feb 1 17:47:58 UTC 2008
John Hinton <webmaster at ew3d.com>

Les Mikesell wrote:
> Craig White wrote:
>>>
>>> We will work also with the Red Hat Security team and see if we can 
>>> isolate any issues that might be FIXABLE.
>> ----
>> doesn't this almost beg for upstream to make denyhosts a base install
>> and automatically on, just as sshd is automatically on?
>
> I've always wondered why a program like sshd didn't rate-limit 
> connection attempts from day one.  It's not exactly a new concept, 
> especially for a security-oriented program.
>
I actually think RedHat has moved backwards in this area. I'm seeing 
dictionary attacks on ssh, vsftp, dovecot, samba, virtually every 
service which might be available out to the web. Gaining access in any 
of these areas is the first step to a compromised system.

ssh and vsftp seem to be the most often attacked... I have had ssh set 
to deny all and allow only known IP addresses of known users who need 
the service... still not perfect by any means, as somewhere along the 
line someone is going to need access while their connection is 
dynamic... just hadn't hit that one yet.

I have to wonder about vsftp... Yes it's fast, but I wonder if some of 
this speed comes from not doing checks that really need to be done, like 
keeping up with multiple failed logins. Seems like wu and pro both had 
settings for this within their config files? But, even if we take the 
UNIX ideal for doing things, the modular approach... I am very surprised 
that RHEL doesn't appear to have any system within the provided packages 
which can be set to deal with the various servers in some straight 
forward manner. Yes, there are programs out there. I'm running one of 
them. But why are we left with this one shortcoming by upstream?

Sorry, this just seems to be really odd to me. Dealing with each 
external system, is dealing with yet one more system to follow. Each 
time, there may be a new issue introduced with regards to a conflict on 
a server... the whole reason for following upstream as much as possible. 
Each one also introduces the need to follow another mailing list. It's 
just not very efficient nor as safe, when compared to yum or up2date 
updates.

As for changes to passwords. Sure, changing the root password is a great 
idea. But then, what about all the users? It's absurd to consider making 
all the users on a hosting server change their passwords once a month, 
once a year or even once every ten years. They can barely keep up with 
the one they have and many don't. Most don't know how to configure their 
email client. Entry into a system from any service opens up a lot of 
potentials. I really don't get why there is not a system in place to 
deal with this just as we have selinux, suexec, etc.

John Hinton