The remote host is vulnerable to a local privilege escalation flaw.
The remote host is running SSH Tectia Server, a commercial SSH server. According to its banner, the installed version of this software contains a local flaw in the way that it handles command line arguments to the 'ssh-signer' binary. This flaw is only relevant to Unix machines. An attacker exploiting this flaw would need local access. Successful exploitation would result in the attacker executing code as the 'root' user.
Upgrade to version 5.2.4, 5.3.6 or higher.