Re: significant incoming SSH volume

[Michael Horne <Michael.Horne () OLIN EDU>]

All,

We have a single SSH gateway for all inbound ssh traffic to the college. Single point of access and control for all 
inbound service.
We also have deployed sshdfilter on the server as well and has worked great for us to date.
Brute force attacks get routed to /dev/null after x amount of failed attempts configurable to your liking.
A google search will bring up the source. It is a bit dated and requires updating when newer version of SSH are 
deployed but it mitigates a ton of headaches.


Michael Horne
Network Engineer
Franklin W Olin College of Engineering
Olin Way Needham MA 02492
Phone  1-781-292-2438




From: The EDUCAUSE Security Constituent Group Listserv [mailto:SECURITY () LISTSERV EDUCAUSE EDU] On Behalf Of Justin 
Sipher
Sent: Tuesday, March 16, 2010 4:07 PM
To: SECURITY () LISTSERV EDUCAUSE EDU
Subject: [SECURITY] significant incoming SSH volume

Hello all.  We have seen a drastic uptick in recent days for inbound SSH connections to many of our servers.  These 
connection are attempting to connect to our servers as ROOT and are coming from IP addressed appearing to be mostly 
overseas.  They number in the thousands of connections.  While we are confident in the strength of our passwords, as 
you know with enough effort.......

My questions to this group are:


 *   Is anyone else seeing this?


 *   Are you doing anything to address this?  We are contemplating blocking SSH inbound on our firewall and requiring 
any external SSH connection to first connect to our VPN.  In some ways it seems excessive and maybe even unsustainable. 
 On the other hand, protecting our servers is important as you well know.

Any advice, feedback, or suggestion of best practice is welcome.

Best & thanks!
...Justin
________________________
  Justin Sipher
  Chief Technology Officer
  Skidmore College
  Saratoga Springs, NY
  jsipher () skidmore edu<mailto:jsipher () skidmore edu>
  518-580-5909