Incomplete validation in boosted trees code

Impact

The code for boosted trees in TensorFlow is still missing validation. As a result, attackers can trigger denial of service (via dereferencing nullptrs or via CHECK-failures) as well as abuse undefined behavior (binding references to nullptrs). An attacker can also read and write from heap buffers, depending on the API that gets used and the arguments that are passed to the call.

Note: Given that the boosted trees implementation in TensorFlow is unmaintained, it is recommend to no longer use these APIs. Instead, please use the downstream TensorFlow Decision Forests project which is newer and supports more features. We will deprecate TensorFlow's boosted trees APIs in subsequent releases.

Patches

We have patched the issue in GitHub commit 5c8c9a8bfe750f9743d0c859bae112060b216f5c.

The fix will be included in TensorFlow 2.7.0. We will also cherrypick this commit on TensorFlow 2.6.1, TensorFlow 2.5.2, and TensorFlow 2.4.4, as these are also affected and still in supported range.

For more information

Please consult our security guide for more information regarding the security model and how to contact us with issues and questions.

Attribution

This vulnerability has been reported by members of the Aivul Team from Qihoo 360.