Man-In-the-Middle attack

Posted by Roshan on Mar 11, 2016; 5:47am
URL: http://erman-arslan-s-oracle-forum.124.s1.nabble.com/Man-In-the-Middle-attack-tp712.html

Oracle linux 6.5
Oracle Database 11gR2
EBSR12.2.4

Hello Erman,

when I do scp <foldername> username@<IP>:<path> I get the error below:
[root@erppreprod db]# scp 11.2.0BK root@172.**.**.***:/u0*/oracle/****/db
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    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
83:54:3a:46:e6:fb:4b:cc:48:44:de:61:b4:79:4e:b0.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending key in /root/.ssh/known_hosts:2
RSA host key for 172.25.43.147 has changed and you have requested strict checking.
Host key verification failed.
lost connection

Then I ran the command below as root and the issue was solved:
sed -i '2d' /home/oracle/.ssh/known_hosts

But as appltest user and oratest user I am getting the error below:

[appltest@erppreprod01 ~]$ sed -i '2d' /home/oracle/.ssh/known_hosts
sed: can't read /home/oracle/.ssh/known_hosts: No such file or directory

Thanks,
Roshan