CVE-2021-32693: Authentication granted with multiple firewalls

Description -----------

When an application defines multiple firewalls, the authenticated token delivered by one of the firewalls is available to all other firewalls. This can be abused when the application defines different providers for different parts of an application. In such a situation, a user authenticated on one part of the application is considered authenticated on the whole application.

Resolution ----------

We now ensure that the authenticated token is only available for the firewall that generates it.

The patch for this issue is available here for branch 5.3.

Credits -------

I would like to thank Bogdan, gndk, Paweł Warchoł, Warxcell, and Adrien Lamotte for reporting the issue and Wouter J for fixing the issue.

— GitHub

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. A vulnerability related to firewall authentication is in Symfony starting with version 5.3.0 and prior to 5.3.2. When an application defines multiple firewalls, the token authenticated by one of the firewalls was available for all other firewalls. This could be abused when the application defines different providers for each part of the application, in such a situation, a user authenticated on a part of the application could be considered authenticated on the rest of the application. Starting in version 5.3.2, a patch ensures that the authenticated token is only available for the firewall that generates it.

— MITRE