What is Trust Exploitation Attack?
The goal of a trust exploitation attacker is to compromise a trusted host, using it to stage attacks on other hosts in a network.
If a host in a network of a company is protected by a firewall (inside host), but is accessible to a trusted host outside the firewall (outside host), the inside host can be attacked through the trusted outside host.
Trust exploitation-based attacks can be controlled through strict protocols on trust levels within a network, for example, private VLANs can be deployed in public-service segments where multiple public servers are available.
Systems on the outside of a firewall should never be totally trusted by systems on the inside of a firewall. Such trust should be limited to specific protocols and should be authenticated by something other than an IP address.