When this was first announced back in 2014, Brian Krebs reported on how much of a threat these kinds of birthday attacks were, but I have not been able to find a case study of a successful breach.
Is there anything in the public domain that goes beyond theory and shows where an exploit using Poodle, Beast or Sweet32 was successful?
It is unlikely that there is public knowledge about use of these attacks in the practice. These issues are far from simple to exploit. It is usually much easier and cheaper to use the more common attacks and only fall back to the complex and expensive attacks if there is no other way but the target is still worth the effort. This means one can expect that only high-value targets will be affected by this and reports of such attacks will thus not be publicly available.
