CVE-2023-27496 MEDIUM

CVE-2023-27496: Envoy may crash when a redirect url without a state param is received in the oauth filter

Vendor Envoyproxy
Product envoy
Weakness CWE-20 · Input validation
Published April 4, 2023
Last update February 10, 2025

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

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 OAuth filter assumes that a `state` query param is present on any response that looks like an OAuth redirect response. Sending it a request with the URI path equivalent to the redirect path, without the `state` parameter, will lead to abnormal termination of Envoy process. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 contain a patch. The issue can also be mitigated by locking down OAuth traffic, disabling the filter, or by filtering traffic before it reaches the OAuth filter (e.g. via a lua script).

Key dates

02Disclosure timeline

April 4, 2023 CVE published
February 10, 2025 Record updated