Auth0 Symfony SDK Vulnerable to Brute Force Authentication Tags of CookieStore Sessions

Overview Session cookies of applications using the Auth0 symfony SDK configured with CookieStore have authentication tags that can be brute forced, which may result in unauthorized access.

Am I Affected? You are affected by this vulnerability if you meet the following pre-conditions:

1. Applications using the Auth0 symfony SDK with version <=5.3.1
2. Auth0/Symfony SDK uses the Auth0-PHP SDK with version 8.0.0-BETA1 or higher and below 8.14.0.
3. Session storage configured with CookieStore.

Fix Upgrade Auth0/symfony to v5.4.0. As an additional precautionary measure, we recommend rotating your cookie encryption keys. Note that once updated, any previous session cookies will be rejected.

Acknowledgement Okta would like to thank Félix Charette for discovering this vulnerability.