Symfony >= 5.3.0, <5.3.2 versions of the Symfony Security HTTP component is affected by this security issue.
The issue has been fixed in Symfony 5.3.2.
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.
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.
I would like to thank Bogdan, gndk, Paweł Warchoł, Warxcell, and Adrien Lamotte for reporting the issue and Wouter J for fixing the issue.
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