Ruby on Rails Web Console before 2.1.3, as used with Ruby on Rails 3.x and 4.x, does not properly restrict the use of X-Forwarded-For headers in determining a client’s IP address, which allows remote attackers to bypass the whitelisted_ips protection mechanism via a crafted request to request.rb.
View the template here CVE-2015-3224.yaml
References:
https://nvd.nist.gov/vuln/detail/CVE-2015-3224