From 9e9056627b07a369354f6362ea782d3de91bd3a0 Mon Sep 17 00:00:00 2001 From: kisfenyo Date: Thu, 1 Oct 2026 21:03:11 +0200 Subject: [PATCH] gokapi: remove the client-written X-Forwarded-For chain on its router (R-753) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit leftmost XFF into its download log (SaveIp). Once traefik trusts the tunnel's fixed address (controller v0.286.0), the leftmost entry is what a stranger writes; with the chain removed the app reads traefik's X-Real-Ip or its peer, as before — never forgeable. Measured on 9202: a router with this middleware receives no X-Forwarded-For (felhom.eu audits/visitors-2026-10-01/A/P1). Co-Authored-By: Claude Opus 5.5 (1M context) Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS --- templates/gokapi/docker-compose.yml | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/templates/gokapi/docker-compose.yml b/templates/gokapi/docker-compose.yml index a8ccbb4..0c4d9ee 100644 --- a/templates/gokapi/docker-compose.yml +++ b/templates/gokapi/docker-compose.yml @@ -47,6 +47,10 @@ services: labels: - "traefik.enable=true" - "traefik.http.routers.gokapi.rule=Host(`${SUBDOMAIN}.${DOMAIN}`)" + # R-753: this app reads the LEFTMOST X-Forwarded-For entry, which a stranger writes once traefik keeps the + # tunnel's chain — so its chain is removed here (it then reads traefik's X-Real-Ip or peer; never forgeable). + - "traefik.http.middlewares.gokapi-xff.headers.customrequestheaders.X-Forwarded-For=" + - "traefik.http.routers.gokapi.middlewares=gokapi-xff" - "traefik.http.routers.gokapi.entrypoints=websecure" - "traefik.http.routers.gokapi.tls=true" - "traefik.http.routers.gokapi.tls.certresolver=letsencrypt"