Resolve Warning Ssh Version 1 Possible Allowed From Plesk Watchdog

The error email I get from “watchdog” once a week looks like this:

To fix this problem, we’ll need to edit the sshd_config file, which is the main configuration file for the sshd service. The location will sometimes be different, but it’s usually in /etc/ssh/. Open the file up while logged on as root.

[01:01:51] ————————- Security advisories ————————-[01:01:52] Warning: SSH version 1 possible allowed!

note: Be careful, if you screw this up you won’t be able to ssh to your server anymore…

Find this section in the file, containing the line with “Protocol” in it. Here’s where the problem is… we need to explicitly tell the sshd service to only use version 2.

If the line is commented out or has both 2,1 in it, you’ll need to make it look like this (leave the other lines alone)

Now you’ll need to restart the sshd service:

You shouldn’t get those error emails anymore.