Description
This endpoint is possibly vulnerable to URL redirection attacks.
URL redirection is sometimes used as a part of phishing attacks that confuse visitors about which web site they are visiting.
Remediation
Your script should properly sanitize user input.
References
Unvalidated Redirects and Forwards Cheat Sheet
HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
Related Vulnerabilities
WordPress Plugin Age Gate Open Redirect (2.13.4)
WordPress 4.1.x Multiple Vulnerabilities (4.1 - 4.1.22)
WordPress 4.8.x Multiple Vulnerabilities (4.8 - 4.8.20)
WordPress Plugin moreAds SE Open Redirect (1.4.8)
WordPress URL Redirection to Untrusted Site ('Open Redirect') Vulnerability (CVE-2019-16220)