Zenoss Core through 5 Beta 3 does not require complex passwords, which makes it easier for remote attackers to obtain access via a brute-force attack, aka ZEN-15406.
https://docs.google.com/spreadsheets/d/1dHAc4PxUbs-4Dxzm1wSCE0sMz5UCMY6SW3PlMHSyuuQ/edit?usp=sharing