CVEs-PoC/2021/CVE-2021-23385.md

### [CVE-2021-23385](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-23385)
![](https://img.shields.io/static/v1?label=Product&message=Flask-Security&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3E%3D%200%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Open%20Redirect&color=brighgreen)

### Description

This affects all versions of package Flask-Security. When using the get_post_logout_redirect and get_post_login_redirect functions, it is possible to bypass URL validation and redirect a user to an arbitrary URL by providing multiple back slashes such as \\\evil.com/path. This vulnerability is only exploitable if an alternative WSGI server other than Werkzeug is used, or the default behaviour of Werkzeug is modified using 'autocorrect_location_header=False. **Note:** Flask-Security is not maintained anymore.

### POC

#### Reference
- https://security.snyk.io/vuln/SNYK-PYTHON-FLASKSECURITY-1293234
- https://snyk.io/blog/url-confusion-vulnerabilities/

#### Github
- https://github.com/ARPSyndicate/cvemon