The report has a top ten list of vendors with
the most vulnerability disclosures. Can you guess which one of Drupal, Joomla or WordPress shows up on the list?
If you answered 'all of them', you were right on the money. Joomla is at the number two spot, while Drupal and WordPress are 8th and 9th place on the list. Funny that all three of those use PHP, but I'm not saying it has anything to do with this (I'm thinking it, but I'm not saying it).
The reason Plone is not on this list? Well, for one thing, we may be flying below IBM's radar (the word Plone does not appear on this study at all), but I think Zope 2 is indeed more secure. Consider also that one of the most common types of attack according to the study is SQL injection, to which Plone is immune by virtue of not using a relational database at all.