Slipstream
NAT Slipstreaming allows an attacker to remotely access any TCP/UDP
...The attack is able to bypass browser port restrictions by fragmenting or massaging packets so that the “exploit payload” lands in a packet boundary that gets parsed by the NAT/ALG as a legitimate protocol packet (e.g. SIP or H.323). Once successful, the NAT/firewall is deceived into opening a “hole” (port forwarding) back to the internal host, enabling the attacker to connect directly to internal services.