cve/2023/CVE-2023-35943.md

### [CVE-2023-35943](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-35943)
![](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%201.26.0%2C%20%3C%201.26.4%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-416%3A%20Use%20After%20Free&color=brighgreen)

### Description

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, the CORS filter will segfault and crash Envoy when the `origin` header is removed and deleted between `decodeHeaders`and `encodeHeaders`. Versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 have a fix for this issue. As a workaround, do not remove the `origin` header in the Envoy configuration.

### POC

#### Reference
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-mc6h-6j9x-v3gq

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