use strict;
use warnings;
use Net::SSH::Perl;
use Net::SSH::Perl::Constants qw( :msg );

my $ssh = Net::SSH::Perl->new($user);
$ssh->login($username, $password);

$ssh->register_handler(
    SSH_SMSG_STDERR_DATA, sub{
        my ( $ssh, $packet ) = @_;
        my $str = $packet->get_str;
        if ( $str =~ /Password/ ) {
            my $packet = $ssh->packet_start(SSH_CMSG_STDIN_DATA);
            $packet->put_str($password);
            $packet->send;
        }
    }
);

$ssh->cmd('ssh second_host');
$ssh->cmd('run cmd on second host');