CVE-2021-33852: 
WordPress vulnerability analysis and mitigation

A stored cross-site scripting (XSS) vulnerability was identified in WordPress Post Duplicator Plugin versions below 2.27, tracked as CVE-2021-33852. The vulnerability was discovered on December 28, 2021, and was publicly disclosed on December 2, 2021. The issue affects the plugin's Settings Page and specifically involves the 'Duplicate Title' and 'Duplicate Slug' fields, which fail to properly sanitize and escape user input (CSW Report, WPScan).

The vulnerability exists due to improper sanitization and escaping of the Duplicate Title and Slug settings in the Post Duplicator plugin. The XSS payload executes when users open either the Settings Page of the Post Duplicator Plugin or the application root page after duplicating existing posts. The vulnerability has been assigned a CVSS score of 3.4 (low severity) and is classified under CWE-79. The issue persists even when the unfiltered_html capability is disallowed (WPScan).

The vulnerability allows attackers to inject malicious JavaScript code that executes in users' browsers while connected to the trusted website. Potential impacts include the ability to modify code and obtain session information of other users, as well as potentially compromising user machines. The attack uses the application as a vehicle to target application users (CSW Report).

The vulnerability has been fixed in Post Duplicator version 2.27. Recommended mitigations include performing context-sensitive encoding of untrusted input before echoing it back to browsers, implementing input validation for special characters, explicitly setting character set encoding for each page, and encoding dynamic output elements. Users should update to the latest version of the plugin (WPScan, CSW Report).