CVE-2023-27487: Envoy client may fake the header `x-envoy-original-path`
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, the client may bypass JSON Web Token (JWT) checks and forge fake original paths. The header x-envoy-original-path should be an internal header, but Envoy does not remove this header from the request at the beginning of request processing when it is sent from an untrusted client. The faked header would then be used for trace logs and grpc logs, as well as used in the URL used for jwtauthn checks if the jwtauthn filter is used, and any other upstream use of the x-envoy-original-path header. Attackers may forge a trusted x-envoy-original-path header. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 have patches for this issue.
Other sources
The header x-envoy-original-path should be an internal header, but Envoy does not remove this header from the request at the beginning of request processing when it is sent from an untrusted client.
The faked header would then be used for trace logs and grpc logs, as well as used in the URL used for jwtauthn checks if the jwtauthn filter is used, and any other upstream use of the x-envoy-original-path header.
— Red Hat
Affected Software
Event History
Frequently Asked Questions
What is CVE-2023-27487?
CVE-2023-27487 is a vulnerability in Envoy that allows the client to bypass JSON Web Token (JWT) checks and forge fake original paths.
What is the severity of CVE-2023-27487?
CVE-2023-27487 has a severity rating of 9.1 (Critical).
Which versions of Envoy are affected by CVE-2023-27487?
Versions 1.22.9, 1.23.0 to 1.23.6, 1.24.0 to 1.24.4, and 1.25.0 to 1.25.3 of Envoy are affected by CVE-2023-27487.
How can the client bypass JSON Web Token (JWT) checks in CVE-2023-27487?
The client can bypass JWT checks in CVE-2023-27487 by using the header 'x-envoy-original-path' to forge fake original paths.
Is there a fix for CVE-2023-27487?
Yes, upgrading to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, or 1.22.9 of Envoy fixes the vulnerability CVE-2023-27487.