Traefik routes exposed with an empty TLSOption
ImpactThere is a potential vulnerability in Traefik managing the TLS connections.A router configured with a not well-formatted [TLSOption](https://doc.traefik.io/traefik/v2.9/https/tls/#tls-options) is exposed with an empty TLSOption.For instance, a route secured using an mTLS connection set with a wrong CA file is exposed without verifying the client certificates.Patcheshttps://github.com/traefik/traefik/releases/tag/v2.9.6WorkaroundsCheck the logs to detect the following error messages and fix your TLS options:Empty CA:Bad CA content (or bad path):Unknown Client Auth Type:Invalid cipherSuitesInvalid curvePreferencesFor more informationIf you have any questions or comments about this advisory, please [open an issue](https://github.com/traefik/traefik/issues).