Denial of Service in Tensorflow

Impact

The SparseFillEmptyRowsGrad implementation has incomplete validation of the shapes of its arguments:

https://github.com/tensorflow/tensorflow/blob/0e68f4d3295eb0281a517c3662f6698992b7b2cf/tensorflow/core/kernels/sparse_fill_empty_rows_op.cc#L235-L241

Although reverse_index_map_t and grad_values_t are accessed in a similar pattern, only reverse_index_map_t is validated to be of proper shape. Hence, malicious users can pass a bad grad_values_t to trigger an assertion failure in vec, causing denial of service in serving installations.

Patches

We have patched the issue in 390611e0d45c5793c7066110af37c8514e6a6c54 and will release a patch release for all affected versions.

We recommend users to upgrade to TensorFlow 1.15.4, 2.0.3, 2.1.2, 2.2.1, or 2.3.1.

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 is a variant of [GHSA-63xm-rx5p-xvqr](https://github.com/tensorflow/tensorflow/security/advisories/GHSA-63xm-rx5p-xvqr)