cve/2023/CVE-2023-23934.md

### [CVE-2023-23934](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-23934)
![](https://img.shields.io/static/v1?label=Product&message=werkzeug&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3D%20%3C%202.2.3%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-20%3A%20Improper%20Input%20Validation&color=brighgreen)

### Description

Werkzeug is a comprehensive WSGI web application library. Browsers may allow "nameless" cookies that look like `=value` instead of `key=value`. A vulnerable browser may allow a compromised application on an adjacent subdomain to exploit this to set a cookie like `=__Host-test=bad` for another subdomain. Werkzeug prior to 2.2.3 will parse the cookie `=__Host-test=bad` as __Host-test=bad`. If a Werkzeug application is running next to a vulnerable or malicious subdomain which sets such a cookie using a vulnerable browser, the Werkzeug application will see the bad cookie value but the valid cookie key. The issue is fixed in Werkzeug 2.2.3.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/ARPSyndicate/cvemon
- https://github.com/HotDB-Community/HotDB-Engine
- https://github.com/SenhorDosSonhos1/projeto-voluntario-lacrei