Help with SSH attack..DNS Spoofing

laucian · 10-15-2007, 05:38 AM

Quote:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
The RSA host key for Computer-NAME has changed,
and the key for the according IP address 129.206.xxx.xxx
is unknown. This could either mean that
DNS SPOOFING is happening or the IP address for the host
and its host key have changed at the same time.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
41:08:1f:00:c3:fc:e4:55:77:a1:a4:xx:xx:xx:xx:xx.
Please contact your system administrator.
Add correct host key in /home/USERNAME/.ssh/known_hosts to get rid of this message.
Offending key in /home/USERNAME/.ssh/known_hosts:3
RSA host key for Computer-Name has changed and you have requested strict checking.
Host key verification failed.

hi everybody..
i am having a problem with ssh..
what does this mean..how can i secure my system..?

Guttorm · 10-15-2007, 06:17 AM

Hi

When you install ssh on a server, a host key is created. The message you get is telling you that this key has changed. Usually this happens when someone does a reinstall of the server. It could also be that there is something happening, like DNS spoofing.

The computer (operating system) you reach when you do a "ssh Computer-NAME" is not the same as last time you connected with ssh. If you know the reason (like if there has been a reinstall), delete line 3 in the file "/home/USERNAME/.ssh/known_hosts", and try again. If not, I would contact the administrator of that server and ask what's going on.