In Apache Zeppelin prior to 0.8.0 the cron scheduler was enabled by default and could allow users to run paragraphs as other users without authentication

Apache Zeppelin prior to 0.7.3 was vulnerable to session fixation which allowed an attacker to hijack a valid user session

The attacker can use the raft server protocol in an unauthenticated way

Authentication bypass vulnerability in Apache Zeppelin allows an attacker to bypass Zeppelin authentication mechanism to act as another user