Flexmls IDX Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the Flexmls IDX Plugin for WordPress, affecting all versions through 3.14.27. The issue arises from inadequate input sanitization and output escaping on user-supplied attributes within the 'idx_frame' shortcode. This vulnerability allows authenticated attackers with contributor-level access or higher to inject arbitrary scripts into pages, which are executed when users access the affected pages.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, where injected scripts are executed in the context of the user viewing the page.

Reproduction

To reproduce this vulnerability, an authenticated user with contributor-level access or higher can use the 'idx_frame' shortcode to inject scripts. The lack of proper sanitization and escaping on the shortcode's attributes allows the injected scripts to be executed when the page is viewed.

Remediation

Users are advised to update the Flexmls IDX Plugin to version 3.14.29 or later.