CVE-2022-23632 Information

Description

Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.6.1 Traefik skips the router transport layer security (TLS) configuration when the host header is a fully qualified domain name (FQDN). For a request the TLS configuration choice can be different than the router choice which implies the use of a wrong TLS configuration. When sending a request using FQDN handled by a router configured with a dedicated TLS configuration the TLS configuration falls back to the default configuration that might not correspond to the configured one. If the CNAME flattening is enabled the selected TLS configuration is the SNI one and the routing uses the CNAME value so this can skip the expected TLS configuration. Version 2.6.1 contains a patch for this issue. As a workaround one may add the FDQN to the host rule. However there is no workaround if the CNAME flattening is enabled.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Reference

https://github.com/traefik/traefik/security/advisories/GHSA-hrhx-6h34-j5hc https://github.com/traefik/traefik/pull/8764 https://github.com/traefik/traefik/releases/tag/v2.6.1

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

9.8