Information disclouse and DoS via websocket push events

Improper Authorization vulnerability in OTRS AG OTRS 8 (Websocket API backend) allows any as Agent authenticated attacker to track user behaviour and to gain live insight into overall system usage. User IDs can easily be correlated with real names e. g. via ticket histories by any user. (Fuzzing for garnering other adjacent user/sensitive data). Subscribing to all possible push events could also lead to performance implications on the server side, depending on the size of the installation and the number of active users. (Flooding)This issue affects OTRS: from 8.0.X before 8.0.32.