Division by zero in TFLite's implementation of `EmbeddingLookup`
The implementation of the `EmbeddingLookup` TFLite operator is vulnerable to a division by zero error
https://github.com/tensorflow/tensorflow/blob/e4b29809543b250bc9b19678ec4776299dd569ba/tensorflow/lite/kernels/embedding_lookup.cc#L73-L74:
```cc
const int row_size = SizeOfDimension(value, 0);
const int row_bytes = value->bytes / row_size;
```
An attacker can craft a model such that the first dimension of the `value` input is 0.
### Patches
We have patched the issue in GitHub commit f61c57bd425878be108ec787f4d96390579fb83e
https://github.com/tensorflow/tensorflow/commit/f61c57bd425878be108ec787f4d96390579fb83e.
The fix will be included in TensorFlow 2.5.0. We will also cherrypick this commit on TensorFlow 2.4.2, TensorFlow 2.3.3, TensorFlow 2.2.3 and TensorFlow 2.1.4, as these are also affected and still in supported range.
### For more information
Please 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.
### Attribution
This vulnerability has been reported by members of the Aivul Team from Qihoo 360.