WordPress Visitor Statistics (Real Time Traffic) plugin before 4.8 does not properly sanitize and escape the refUrl in the refDetails AJAX action, which is available to any authenticated user. This could allow users with a role as low as subscriber to perform SQL injection attacks.
View the template here CVE-2021-24750.yaml
References:
https://wpscan.com/vulnerability/7528aded-b8c9-4833-89d6-9cd7df3620de