A circuit-level gateway accepts a trusted client's requests for specific services and, after verifying the legitimacy of a requested session, establishes a connection with an untrusted host. In the case of firewalls, a data driven attack is a concern since it may get through the firewall in data form and launch an attack against a system behind the firewall. May be used in conjunction with firewalls. A dual-homed gateway relays information between the two networks and prevents any direct contact between them. The technique of securing an individual system from attack.
Host based security is operating system and version dependent.
An attack originating from inside a protected network. An attack whereby a system attempts to illicitly impersonate another system by using its IP network address. An attack whereby an active, established, session is intercepted and co-opted by the attacker. IP Splicing attacks may occur after an authentication has been made, permitting the attacker to assume the role of an already authorized user. Primary protections against IP Splicing rely on encryption at the session or network layer.