The Easy Social Feed – Social Photos Gallery – Post Feed – Like Box plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'efb_likebox' shortcode in all versions up to, and including, 6.5.4 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.