Local Area Networks (LANs) in Aircraft - FTP Directory Listing - FAA

attempt the theft of passwords. None of the e-mails got through to the intended
targets, MessageLabs said, but the U.K. authorities were alerted.” [31]
Network attacks range in severity and purpose, which include:
• Learning about the target environment to discern which entity to attack, using which
attack tools (see appendix A, section A.1). This is known as fingerprinting and consists
of network reconnaissance, mapping, and target acquisition activities.
• Attempting to compromise (i.e., takeover) one or more devices within the target network
(see appendix A, section A.2). Once a device has been successfully cracked (i.e.,
hostilely taken over by an attacker), then the attacker can leverage that device to attack
other entities within the network.
• Attempting to attack the network distribution system itself (see appendix A, section A.3).
This is often accomplished by availability attacks such as DoS attacks.
• Attempting to attack the data that traverses the network (see appendix A, section A.4).
This consists of integrity and confidentiality attacks.
All entities within a network are potentially subject to electronic attack. Entities include the
devices and software present within the network, the (physical) communications links, and the
communications protocols used within the network. Figure 10 shows a network deployment
example. The figure shows that there are three types of devices that can be present within an IP
network:
• Hosts (e.g., computers, which are known in OSI terminology as end-systems) are the
source and/or sink of end-user communications.
• Routers (known in OSI terminology as the network layer intermediate system element)
perform IP forwarding of communications between network elements. 6
• Middleboxes are defined by Request for Comment (RFC) 3234 as “any intermediary box
performing functions apart from [the] normal, standard functions of an IP router on the
data path between the source host and destination host.” Figure 10 shows three different
examples of middleboxes:
- Network Address Translator (NAT)—a device that dynamically assigns a
globally unique IP address (without the hosts’ knowledge) to hosts that do not
have one.
- Protocol Translation Gateway—a device that translates communication protocols
between dissimilar protocol systems (e.g., mapping between IP and OSI (e.g.,
ATN) networks).
6 See the IP Topology Hierarchy section below (section 5.3) for a description of network hierarchy elements.
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