Description
WordPress Plugin Contact Form Check Tester is prone to a cross-site scripting vulnerability because it fails to properly sanitize user-supplied input. An attacker may leverage this issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This can allow the attacker to steal cookie-based authentication credentials and launch other attacks. WordPress Plugin Contact Form Check Tester version 1.0.2 is vulnerable; prior versions may also be affected.
Remediation
Disable and remove the plugin until a fix is available
References
https://sploitus.com/exploit?id=WPEX-ID:E2990A7A-D4F0-424E-B01D-ECF67CF9C9F3
https://wordpress.org/plugins/contact-form-check-tester/#description