GoFiber Vulnerable to X-Real-IP Spoofing via Header.Add() in BalancerForward

Summary The BalancerForward proxy helper in GoFiber uses Header.Add instead of Header.Set when injecting the X-Real-IP header. This appends the real client IP as a second header value rather than replacing any attacker-supplied value. Upstream servers that read the first X-Real-IP header nginx,...