CVE-2020-5275: Firewall configured with unanimous strategy was not actually unanimous in symfony/security-http

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

On Symfony before 4.4.0, when a Firewall checks an access control rule (using the unanimous strategy), it iterates over all rule attributes and grant access only if all calls to the accessDecisionManager decide to grant access.

As of Symfony 4.4.0, a bug was introduced that prevents the check of attributes as soon as accessDecisionManager decide to grant access on one attribute.

Resolution ----------

The accessDecisionManager is now called with all attributes at once, allowing the unanimous strategy being applied on each attribute.

The patch for this issue is available here for the 4.4 branch.

Credits -------

I would like to thank Antonio J. García Lagar for reporting & Robin Chalas for fixing the issue.

— GitHub

In symfony/security-http before versions 4.4.7 and 5.0.7, when a Firewall checks access control rule, it iterate overs each rule's attributes and stops as soon as the accessDecisionManager decides to grant access on the attribute, preventing the check of next attributes that should have been take into account in an unanimous strategy. The accessDecisionManager is now called with all attributes at once, allowing the unanimous strategy being applied on each attribute. This issue is patched in versions 4.4.7 and 5.0.7.