Intermediaries: The jump server is not a magic shield
Jun 4th, 2022 by Jesper Kråkhede
Fourth area from the privileged access strategy: intermediaries. In plain words, all the things that sit between the user and the system. VPNs, jump servers, remote desktop gateways, privileged access management solutions.
I have a confession. Every time someone tells me ‘it´s okay, all admin access goes through the jump server’, a small part of me dies.
Because a jump server is a server. It has an operating system that needs patching. It has local admins. People log on to it with their privileged accounts, which means their credentials are on it. If an attacker gets onto the jump server, he has just found the one place where all your admins leave their keys. It is not a shield. It is a buffet.
The strategy is clear on this. An intermediary must be protected at the same level as the most sensitive thing it gives access to. If the jump server reaches domain controllers, it is part of the control plane and must be treated that way. Hardened, patched, monitored, and only reachable from PAWs.
Better yet, reduce the number of intermediaries. Use modern solutions that check the identity and device before the connection is made, instead of opening a network path and hoping for the best.
Every step between the admin and the target is another place to attack. Protect each step like it was the target.