Login No Captcha reCAPTCHA <= 1.6.11 - CAPTCHA Bypass via Whitelisted IP Address Spoofing

The Login No Captcha reCAPTCHA plugin for WordPress is vulnerable to CAPTCHA bypass in versions up to, and including, 1.6.11. This is due to the whitelisted IP address functionality relying on user-supplied IP addresses from an HTTP Header. If an attacker can gain access to a whitelisted IP address they can spoof the request to come from one of those IP addresses using an HTTP header which would bypass any restrictions.