CVE-2022-23632: 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...

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.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.69%

74.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-295

Affected Software

Vendor	Product	Versions
Traefik	Traefik	< 2.6.1
Oracle	Communications Unified Inventory Management	7.5.0

References

https://github.com/traefik/traefik/pull/8764Issue Tracking, Patch, Third Party Advisory
https://github.com/traefik/traefik/releases/tag/v2.6.1Release Notes, Third Party Advisory
https://github.com/traefik/traefik/security/advisories/GHSA-hrhx-6h34-j5hcPatch, Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.htmlThird Party Advisory
https://github.com/traefik/traefik/pull/8764Issue Tracking, Patch, Third Party Advisory
https://github.com/traefik/traefik/releases/tag/v2.6.1Release Notes, Third Party Advisory
https://github.com/traefik/traefik/security/advisories/GHSA-hrhx-6h34-j5hcPatch, Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.htmlThird Party Advisory

Timeline

Published: Feb 17, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2022-23632?

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.

How severe is CVE-2022-23632?

CVE-2022-23632 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.69% probability of exploitation in the next 30 days.

How do I fix CVE-2022-23632?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.