CVE-2021-24973: 
WordPress vulnerability analysis and mitigation

CVE-2021-24973 is a Cross-Site Scripting (XSS) vulnerability affecting the Site Reviews WordPress plugin versions below 5.17.3. The vulnerability was discovered and publicly disclosed on December 6, 2021, by security researcher Krzysztof Zając (WPScan).

The vulnerability exists because the plugin fails to properly sanitize and escape the site-reviews parameter of the glsr_action AJAX action. This functionality is accessible to both unauthenticated and authenticated users. The vulnerability has been assigned a CVSS score of 8.8 (high) and is classified as CWE-79 (Cross-Site Scripting) (WPScan).

When exploited, this vulnerability allows attackers to perform Cross-Site Scripting attacks against logged-in administrators who view the Tool dashboard of the plugin. The XSS payload is triggered when accessing the plugin's Tool dashboard at /wp-admin/edit.php?post_type=site-review&page=glsr-tools (WPScan).

The vulnerability can be exploited by sending a specially crafted POST request to the WordPress admin-ajax.php endpoint with the glsr_action parameter. No authentication is required to exploit this vulnerability, making it particularly dangerous (WPScan).

The vulnerability has been fixed in Site Reviews version 5.17.3. Site administrators are strongly advised to update to this version or later to protect against potential attacks (WPScan).