Fiber vulnerabilities

In the Fiber web framework for Go prior to version 3.4.0, the helmet middleware incorrectly checks the protocol using c.Protocol() instead of c.Scheme(), causing the Strict-Transport-Security header to never be set even when HSTSMaxAge is configured. This issue is fixed in version 3.4.0.

In the Fiber web framework for Go, prior to versions 3.3.0 and 2.52.14, the BalancerForward proxy helper in middleware/proxy/proxy.go uses Header.Add() instead of Header.Set() when injecting the X-Real-IP header. This allows an attacker to supply a first X-Real-IP value that gets forwarded to upstream servers for logging, rate limiting, and access control.

In the Fiber web framework for Go prior to version 3.3.0, the default Authorizer function in the BasicAuth middleware uses short-circuit evaluation that skips password hash comparison for non-existent usernames. This allows reliable remote username enumeration through response timing differences.