fix: add login rate limiting and prevent IP spoofing via headers

- Add RateLimitMiddleware(10/min) to POST /login (previously unprotected)
- Use RemoteAddr instead of X-Real-IP/X-Forwarded-For in getRemoteIp() and rate limiter
- Prevents brute-force login and rate-limit bypass via spoofed headers

docs/Tasktracking/2026-04-25-fix-login-ratelimit-and-ip-spoofing.md

@@ -0,0 +1,18 @@
+# 2026-04-25 Security: Fix login rate limiting and IP spoofing
+
+## Changes
+- Add `RateLimitMiddleware(10, time.Minute)` to `POST /login` endpoint (was unprotected, only register had rate limiting)
+- Fix `getRemoteIp()` to use `c.Request.RemoteAddr` instead of trusting `X-Real-IP` / `X-Forwarded-For` headers
+- Fix `RateLimitMiddleware` to use `RemoteAddr` directly, preventing IP-based rate limit bypass via header spoofing
+
+## Security Issue
+- Login endpoint had zero rate limiting, enabling unlimited brute-force attempts
+- Both IP extraction and rate limiter trusted client-supplied headers, allowing attackers to spoof IPs and bypass all rate limiting
+
+## Files Modified
+- `web/controller/index.go` — add rate limit middleware to login route
+- `web/controller/util.go` — use RemoteAddr in getRemoteIp()
+- `web/middleware/ratelimit.go` — use RemoteAddr in rate limiter
+
+## Note
+If the panel runs behind a reverse proxy, `RemoteAddr` will show the proxy IP. To restore header-based IP detection, configure `engine.SetTrustedProxies()` in `web/web.go` with the proxy's IP.

web/controller/index.go

@@ -53,7 +53,7 @@ func (a *IndexController) initRouter(g *gin.RouterGroup) {
 	g.GET("/", a.index)
 	g.GET("/logout", a.logout)
 
-	g.POST("/login", a.login)
+	g.POST("/login", middleware.RateLimitMiddleware(10, time.Minute), a.login)
 	g.POST("/register", middleware.RateLimitMiddleware(5, time.Minute), a.register)
 	g.POST("/getTwoFactorEnable", a.getTwoFactorEnable)
 	g.POST("/getTurnstileSiteKey", a.getTurnstileSiteKey)

web/controller/util.go

@@ -3,7 +3,6 @@ package controller
 import (
 	"net"
 	"net/http"
-	"strings"
 
 	"github.com/mhsanaei/3x-ui/v2/config"
 	"github.com/mhsanaei/3x-ui/v2/logger"
@@ -13,17 +12,11 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-// getRemoteIp extracts the real IP address from the request headers or remote address.
+// getRemoteIp extracts the real IP address from the direct connection.
+// Uses RemoteAddr to prevent IP spoofing via X-Real-IP/X-Forwarded-For headers.
+// If the panel is behind a trusted reverse proxy, configure Gin's SetTrustedProxies
+// to re-enable header-based IP detection.
 func getRemoteIp(c *gin.Context) string {
-	value := c.GetHeader("X-Real-IP")
-	if value != "" {
-		return value
-	}
-	value = c.GetHeader("X-Forwarded-For")
-	if value != "" {
-		ips := strings.Split(value, ",")
-		return ips[0]
-	}
 	addr := c.Request.RemoteAddr
 	ip, _, _ := net.SplitHostPort(addr)
 	return ip

web/middleware/ratelimit.go

@@ -37,24 +37,8 @@ func RateLimitMiddleware(maxRequests int, window time.Duration) gin.HandlerFunc
 	}()
 
 	return func(c *gin.Context) {
-		ip := c.GetHeader("X-Real-IP")
-		if ip == "" {
-			ip = c.GetHeader("X-Forwarded-For")
-			if ip != "" {
-				// Take the first IP from X-Forwarded-For
-				if idx := len(ip); idx > 0 {
-					for i, ch := range ip {
-						if ch == ',' {
-							ip = ip[:i]
-							break
-						}
-					}
-				}
-			}
-		}
-		if ip == "" {
-			ip = c.Request.RemoteAddr
-		}
+		// Use RemoteAddr directly to prevent IP spoofing via headers
+		ip := c.Request.RemoteAddr
 
 		mu.Lock()
 		now := time.Now()