Modification of information in transit so as to modify
communications as desired. Examples include removing end-of-session requests
and providing suitable replies, then taking over the unterminated
communications link, modification of an amount in an electronic funds
transfer request, and rewriting Web pages so as to reroute subsequent
traffic through the attacker's site.
Complexity: Modification in transit is
roughly equivalent in complexity to the combination of observation in
transit and insertion in transit, however, because of the real-time
requirements for some sorts of modification in transit, the difficulty of
successful attack may be significantly increased.