A regular Zabbix user with no permission to the Monitoring -> Problems view is still able to call the problem.view.refresh action and therefore still retrieve a list of active problems.
The LDAP 'Bind password' value cannot be read after saving, but a Super Admin account can leak it by changing LDAP 'Host' to a rogue LDAP server. To mitigate this, the 'Bind password' value is now reset on 'Host' change.
A regular Zabbix user can search other users in their user group via Zabbix API by select fields the user does not have access to view. This allows data-mining some field values the user does not have access to.