The plugin does not escape the IP addresses (which can be controlled by attacker via headers such as X-Forwarded-For) of attempted logins before outputting them in the reports table, leading to an Unauthenticated Stored Cross-Site Scripting issue.
Proof of Concept
POST /wp-login.php HTTP/1.1
Accept-Encoding: gzip, deflate
The XSS will be triggered when viewing the report page (/wp-admin/admin.php?page=reports)