Fix SSH Exchange Identification Issue on CPanel

I recently faced an issue when trying to connect through SSH to an account on a VPS. For this specific account, I traditionally use the standard username / password combination and everything used to work properly. However, last time I tried to connect, I faced the following issue:

1
2
$ ssh username@domain.com
ssh_exchange_identification: Connection closed by remote host

Using SSH verbose mode provided little additional information.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
$ ssh username@domain.com -v
OpenSSH_5.9p1 Debian-5ubuntu1.1, OpenSSL 1.0.1 14 Mar 2012
debug1: Reading configuration data /home/jimmy/.ssh/config
debug1: /home/jimmy/.ssh/config line 192: Applying options for *
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to domain.com [1.2.3.4] port 22.
debug1: Connection established.
debug1: identity file /home/jimmy/.ssh/ids/domain.com/username/id_rsa type -1
debug1: identity file /home/jimmy/.ssh/ids/domain.com/username/id_rsa-cert type -1
debug1: identity file /home/jimmy/.ssh/ids/domain.com/id_rsa type -1
debug1: identity file /home/jimmy/.ssh/ids/domain.com/id_rsa-cert type -1
debug1: identity file /home/jimmy/.ssh/id_rsa type -1
debug1: identity file /home/jimmy/.ssh/id_rsa-cert type -1
ssh_exchange_identification: Connection closed by remote host

It seemed as if the connection was trying to use an SSH key to connect instead of the usual username / password.

There is however a simple solution. It requires access to WHM (so if you don’t, you might need to contact your web hosting company) and you’ll need to re-enable password authentication. To do so, simply follow the steps below:

1. Log in as root
2. Go to Security Center » SSH Password Authorization
3. Click on the Disable Password Auth button (see screenshot below)
4. Refresh the page and go back to the SSH Password Authorization page
5. Click on the Enable Password Auth button

This fixed the problem and allowed to connect again using the traditional login / password authentication method.