Fathom Analytics < 3.0.5 - Admin+ Stored Cross-Site Scripting

Description

The plugin is vulnerable to Stored Cross-Site Scripting due to insufficient input validation and escaping via the fathom_site_id parameter found in the ~/fathom-analytics.php file which allowed attackers with administrative user access to inject arbitrary web scripts, in versions up to and including 3.0.4. This affects multi-site installations where unfiltered_html is disabled for administrators, and sites where unfiltered_html is disabled.