Description
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.42, 3.6.11, and 3.7.0-ea.3, when `headerField` is configured with a non-canonical HTTP header name (e.g., `x-auth-user` instead of `X-Auth-User`), an authenticated attacker can inject their own canonical version of that header to impersonate any identity to the backend. The backend receives two header entries — the attacker-injected canonical one is read first, overriding Traefik's non-canonical write. Versions 2.11.42, 3.6.11, and 3.7.0-ea.3 patch the issue.
Problem types
CWE-290: Authentication Bypass by Spoofing
Product status
>= 3.0.0-beta1, < 3.6.11
>= 3.7.0-ea.1, < 3.7.0-ea.3
References
github.com/...raefik/security/advisories/GHSA-qr99-7898-vr7c
github.com/traefik/traefik/releases/tag/v2.11.42
github.com/traefik/traefik/releases/tag/v3.6.11
github.com/traefik/traefik/releases/tag/v3.7.0-ea.3