From 8975984b6eaa4d52cf60ddb462e4e77bb13311fd Mon Sep 17 00:00:00 2001 From: kisfenyo Date: Thu, 1 Oct 2026 21:02:53 +0200 Subject: [PATCH] ghost: 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 Express trust proxy true — leftmost XFF; its brute-force buckets are keyed by IP (+username). 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/ghost/docker-compose.yml | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/templates/ghost/docker-compose.yml b/templates/ghost/docker-compose.yml index a92f943..a535a10 100644 --- a/templates/ghost/docker-compose.yml +++ b/templates/ghost/docker-compose.yml @@ -34,6 +34,10 @@ services: labels: - "traefik.enable=true" - "traefik.http.routers.ghost.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.ghost-xff.headers.customrequestheaders.X-Forwarded-For=" + - "traefik.http.routers.ghost.middlewares=ghost-xff" - "traefik.http.routers.ghost.entrypoints=websecure" - "traefik.http.routers.ghost.tls=true" - "traefik.http.routers.ghost.tls.certresolver=letsencrypt"