On Wed, 30 Jul 1997, Systems Engineer wrote:
Actually people are making it seem that the entire MAE is sending
echo. No one is mounting an attack from there, they are just
look like it is coming from there.
Well thats not entirely true. In effect the victim is indeed being
'attacked' by MAE machines on that network. Look at it like this:
evil.com -> generates packet with forged address as
(victim.com(icmp_echo)) -> destination for spoofed packet (25 .255
From here... all 25 network's broadcast address pass the icmp with
forged address on to all machines using that network. Each machine
abused.net.com (echo_reply) -> victim.com
abused2.net.com (echo_reply) -> victim.com
abused3.othernet.com (echo_reply) -> victim.com
abused4.othernet.com (echo_reply) -> victim.com
Its a rather obnoxious attack, and its not exactly new. Though I do
think that it will get much worse now that smurf.c has been written
is being passed around like candy.
The real problem I see with this particular attack is that there is
nothing short of blocking all ICMPs that 'victim.com' can do. At least
not that I am aware of.
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