My team is testing some products where we have forgone SQL as the back-end. This means that we have stopped executing any security tests around SQL injection. I have this nagging suspicion that while SQL injection is not possible, that other similar injection attacks specific to these other technologies could be possible, but I have not had much time myself to put into researching those. The two non SQL solutions that we are using specifically are HBase(on top of Hadoop) and Cassandra.
Does anyone have any good ideas around how to test this or has anyone found any good reading, examples or approaches to discovering and testing these potential attacks? Alternatively any reading or explanation that could put my mind at ease and convince me these attacks aren't possible? I have searched a bit and had no luck finding any useful information on the subject.