GHSA-m697-4v8f-55qg Header dropping in traefik

• Go github.com/traefik/traefik/v2: < 2.4.13 → fixed in 2.4.13 • Go github.com/traefik/traefik: <= 1.7.30 (no fix yet)

Impact There exists a potential header vulnerability in Traefik's handling of the Connection header. Active exploitation of this issue is unlikely, as it requires that a removed header would lead to a privilege escalation, however, the Traefik team has addressed this issue to prevent any potential abuse. Details If you have a chain of Traefik middlewares, and one of them sets a request header `Important-Security-Header`, then sending a request with the following Connection header will cause it to be removed before the request was sent: ``` curl 'https://example.com' -H "Connection: Important-Security-Header" -0 ``` In this case, the backend does not see the request header `Important-Security-Header`. Patches Traefik v2.4.x: https://github.com/traefik/traefik/releases/tag/v2.4.13 Workarounds No. For more information If you have any questions or comments about this advisory, open an issue.