------------------------------------------------------------------------ Persistent Cross-Site Scripting in Magic Fields 1 WordPress Plugin ------------------------------------------------------------------------ Burak Kelebek, July 2016 ------------------------------------------------------------------------ Abstract ------------------------------------------------------------------------ A Cross-Site Scripting vulnerability was found in the Magic Fields 1 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. ------------------------------------------------------------------------ OVE ID ------------------------------------------------------------------------ OVE-20160724-0020 ------------------------------------------------------------------------ Tested versions ------------------------------------------------------------------------ This issue was successfully tested on Magic Fields 1 version 1.7.1. ------------------------------------------------------------------------ Fix ------------------------------------------------------------------------ This issue is fixed in version 1.7.2 ------------------------------------------------------------------------ Details ------------------------------------------------------------------------ https://sumofpwn.nl/advisory/2016/persistent_cross_site_scripting_in_magic_fields_1_wordpress_plugin.html The Magic Fields plugin lacks a CSRF (nonce) token on the request of adding a magic field. The description field of custom fields lacks output encoding which could result in malicious script inserted by an attacker and executed in the browser. You need to lure a logged-in admin to follow a malicious link containing the poc below. Proof of concept The proof of concept below injects script code in the "description" field when adding a new custom field. ------------------------------------------------------------------------ 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.