The End-User Portal module before 1.0.65 for FreeScout sometimes allows an attacker to authenticate as an arbitrary user because a session token can be sent to the /auth endpoint. NOTE: this module is not part of freescout-helpdesk/freescout on GitHub.
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
Such a scenario is commonly observed when: