cve/2023/CVE-2023-27496.md

### [CVE-2023-27496](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-27496)
![](https://img.shields.io/static/v1?label=Product&message=envoy&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3D%20%3E%3D%201.25.0%2C%20%3C%201.25.3%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-20%3A%20Improper%20Input%20Validation&color=brighgreen)

### Description

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).

### POC

#### Reference
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-j79q-2g66-2xv5

#### Github
No PoCs found on GitHub currently.