Security Basics mailing list archives

Re: Is SSH worth it??


From: Devdas Bhagat <dvb () users sourceforge net>
Date: Thu, 17 Oct 2002 00:21:46 +0530

On 15/10/02 14:39 -0400, Chris Santerre wrote:
You know I always wondered about this method. su - has you input a password.
So If a sysadmin is on a cable modem at home, logs in as normal user w/ ssh,
then does an su - and enters password, How is that any different? You are
being sniffed on the cable network. Keep in mind you can now sniff SSH
packets. So how could this be more secure? So wouldn't a hacker now have
both the first user pass and the su - ?
Because the network traffic in a ssh connection is strongly encrypted
(its Secure shell), the cracker will have to do some rather powerful
decryption to get the password. There was a bug in OpenSSH that would
allow the specific encrypted text to be picked off the network (timing
issues, password characters were sent as sinlge bytes), but that has
been fixed a long time back.
Try snifing ssh encrypted traffic.

Oh, and by using keys, your password never crosses the network at all.

Plus, sudo is a lot more useful in such cases. You can grant relatively
granular access using sudo, without having to divulge the root password.

Hmmmm, given that a large part of admin requires editing of files, 
$sudo vim
:!sh
#

is an easy way to get a root shell without ever using the root
password.

Devdas Bhagat


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