Dear Steffen in case with Open, admin
password was cracked by brute force (since admin cookies were
stolen). It is not possible to access database directly via HTML
widgets just using HTML code, since HTML doesn't execute mysql
queries.
It is very important to remember that
more sophisticated admin password decreases the risk of admin account
being hacked.
Also for security purposes, it is better to turn the ability to add custom HMTL/Javascript code by users off, since universal method for identifying malicious code doesn't exist. Oxwall cuts out most popular malicious codes, and we always improve this system. However, right now it is not possible to be 100 % protected from XSS.