This morning I stumbled across a veritable treasure trove of Oracle Security documents at the web site of the Defense Information Systems Agency.
I've only spent a few minutes glancing through a small sampling of them, and they appear to be fairly comprehensive. When you consider that these are documents used to audit sensitive database installations, it makes a lot of sense that they would cross all the t's and dot all the i's.
The index of documents can be found here: DISA IT Security Documents
As you can see for yourself, there are documents covering security concerns for a number of other systems.