CVE-2021-39345
The HAL WordPress plugin is vulnerable to Stored Cross-Site Scripting due to insufficient input validation and sanitization via several parameters found in the ~/wp-hal.php file which allowed attackers with administrative user access to inject arbitrary web scripts, in versions up to and including 2.1.1. This affects multi-site installations where unfiltered_html is disabled for administrators, and sites where unfiltered_html is disabled.
Source: CVE-2021-39345