*XSS and Uncontrolled redirect Vulns in Encrypted Blog Plugin for Wordpress*

# Date: 28 August 2013
# Author: k3170makan
# Vendor or Software Link: http://wordpress.org/plugins/encrypted-blog/
# Version: 0.0.6.2
# Category: webapps
# Tested on: N/A

The Encrypted Blog Plug-in for Wordpress suffers from multiple
vulnerabilities exposing authenticated wordpress users to Cross Site
Scripting attacks and Uncontrolled redirects and via a combination of these
vulnerabilities a leakage of the Encryption key set by the wordpress user.

*Cross Site Scripting:*

The contents of the redirect_to field in the encrypt_blog_form.php, which
is supplied via GET method is not sanitized and allows attackers to submit
malicious HTML/JavaScript and other client side browser scripting content.

Here's the code:
from
https://github.com/marcusds/EncryptedBlog/blob/master/encrypted_blog_form.php

13 <form name="loginform" id="loginform" action="<?php
14  if( isset( $_GET['redirect_to'] ) && !empty( $_GET['redirect_to'] ) )
15  {
16    *echo $_GET['redirect_to'];*
17    if( strpos( $_GET['redirect_to'], '?' ) === false && substr(
$_GET['page'], -1 ) !== '/') {
18      echo '/';
19    }
20  }
21  else
22  {
23    echo './';
24  }

line 16 shows the that the echo is done without parsing the redirect_to
field's value or remove any
potentially malicious HMTL.
PoC: http://imgur.com/S9L4FeV

*Uncontrolled Redirect:*

The uncontrolled redirect stems the following
code:https://github.com/marcusds/EncryptedBlog/blob/master/encrypted_blog_form.php#L43


line 43 shows that unsanitized and uncontrolled data from the redirect_to
field is used to build redirects, meaning that attackers will be able to
redirect victims to arbitrary domains.
PoC: http://imgur.com/LrWmB77

-- 
<Keith k3170makan <http://about.me/k3170makan> Makan/>
blog.k3170makan.com