Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.26 until 2.11.57 and 3.7.13, Traefik forwards a client-supplied Connection header requesting Upgrade, the Upgrade: h2c token, and HTTP2-Settings to a shared backend. If the backend accepts h2c and returns 101 Switching Protocols, Traefik enters a raw tunnel and no longer applies routers, BasicAuth, ForwardAuth, IPAllowList, RateLimit, access logging, metrics, or tracing to later HTTP/2 requests, allowing an unauthenticated request through an unprotected route to reach protected paths on the same backend.
This issue is fixed in 2.11.57 and 3.7.13.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products 2
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Traefik Traefik
cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*
|
2.11.26
|
2.11.57
|
|
Traefik Traefik
cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*
|
3.4.2
|
3.7.13
|
References 5
https://github.com/traefik/traefik/commit/a277e94664ffc1ce9543df552d3bbf48d4d3b…
security-advisories@github.com
https://github.com/traefik/traefik/pull/13797
security-advisories@github.com
https://github.com/traefik/traefik/releases/tag/v2.11.57
security-advisories@github.com
https://github.com/traefik/traefik/releases/tag/v3.7.13
security-advisories@github.com
https://github.com/traefik/traefik/security/advisories/GHSA-w4v4-9rw7-5326
security-advisories@github.com