1## TFSA-2021-168: A use of uninitialized value vulnerability in Tensorflow 2 3### CVE Number 4CVE-2021-41225 5 6### Impact 7TensorFlow's Grappler optimizer has a [use of unitialized variable](https://github.com/tensorflow/tensorflow/blob/3457a2b122e50b4d44ceaaed5a663d635e5c22df/tensorflow/core/grappler/optimizers/auto_parallel.cc#L155-L164): 8 9```cc 10 const NodeDef* dequeue_node; 11 for (const auto& train_node : train_nodes) { 12 if (IsDequeueOp(*train_node)) { 13 dequeue_node = train_node; 14 break; 15 } 16 } 17 18 if (dequeue_node) { 19 ... 20 } 21``` 22 23If the `train_nodes` vector (obtained from the saved model that gets optimized) does not contain a `Dequeue` node, then `dequeue_node` is left unitialized. 24 25### Patches 26We have patched the issue in GitHub commit [68867bf01239d9e1048f98cbad185bf4761bedd3](https://github.com/tensorflow/tensorflow/commit/68867bf01239d9e1048f98cbad185bf4761bedd3). 27 28The 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. 29 30### For more information 31Please consult [our security guide](https://github.com/tensorflow/tensorflow/blob/master/SECURITY.md) for more information regarding the security model and how to contact us with issues and questions. 32 33### Attribution 34This vulnerability has been reported by Qian Feng from Baidu Security Team. 35