The downside is loss of security. Since one's already being MitM'ed, there is no way to ensure the SSH connections aren't compromised. The proper (security-wis

The downside is loss of security. Since one's already being MitM'ed, there is no way to ensure the SSH connections aren't compromised. The proper (security-wise) way to use jumpbox is to ask it to build a tunnel between your local machine and remote host you want to SSH into - then connect over that tunnel. That is, unless you ultimately trust the jumphost or have no interest in security besides the basics necessary to shoo away passive attackers.