Improper input validation in Envoyproxy Envoy

CVE-2023-27496

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).

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.008 (51.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

  • Envoyproxy Envoy — versions >= 1.25.0, < 1.25.3, >= 1.24.0, < 1.24.4, >= 1.23.0, < 1.23.6

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-27496?
CVE-2023-27496 is a medium-severity vulnerability in Envoyproxy Envoy, classified under Improper Input Validation. CVSS score: 6.5/10. Published 2023-04-04.
How severe is CVE-2023-27496?
Medium severity. CVSS v3 base score is 6.5 out of 10.