Vulnerability · Published Feb 17, 2022 · Assigned by GitHub_M
CVE-2022-23632Traefik skips the router TLS configuration when the host header is an FQDN
High 7.4
In plain English
A high-severity improper certificate validation in traefik from traefik. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.7% (higher than 77% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/traefik/traefik | no fix listed | GO-2022-0325 |
| Go | github.com/traefik/traefik/v2 | 2.6.1 | GHSA-hrhx-6h34-j5hc |
| Go | github.com/traefik/traefik/v2 | 2.6.1 | GO-2022-0325 |
Affected products (as reported)
Weakness: CWE-295 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
References
- https://github.com/traefik/traefik/security/advisories/GHSA-hrhx-6h34-j5hc x_refsource_CONFIRM
- https://github.com/traefik/traefik/pull/8764 x_refsource_MISC
- https://github.com/traefik/traefik/releases/tag/v2.6.1 x_refsource_MISC
- https://www.oracle.com/security-alerts/cpujul2022.html x_refsource_MISC