CVE-2021-29566 Heap OOB access in `Dilation2DBackpropInput`

Low 2.5 Published 14 May 2021 Updated 3 Aug 2024

An attacker can trigger heap out-of-bounds writes in TensorFlow's Dilation2DBackpropInput operation, potentially leading to code execution or crashes.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2021-29566?

CVE-2021-29566 is a low-severity memory corruption vulnerability in Google Tensorflow, published on 14 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

TensorFlow is an end-to-end open source platform for machine learning. An attacker can write outside the bounds of heap allocated arrays by passing invalid arguments to `tf.raw_ops.Dilation2DBackpropInput`. This is because the implementation(https://github.com/tensorflow/tensorflow/blob/afd954e65f15aea4d438d0a219136fc4a63a573d/tensorflow/core/kernels/dilation_ops.cc#L321-L322) does not validate before writing to the output array. The values for `h_out` and `w_out` are guaranteed to be in range for `out_backprop` (as they are loop indices bounded by the size of the array). However, there are no similar guarantees relating `h_in_max`/`w_in_max` and `in_backprop`. 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.

Weakness: CWE-787

Which versions are affected by CVE-2021-29566?

28 open source packages ship an affected version, including tensorflow, tensorflow-cpu and tensorflow-gpu. It affects 1 product.

Package	Affected	Fixed in
`tensorflow` Bitnami	All versions	`2.1.4, 2.2.3, 2.3.3, 2.4.2`
`tensorflow` PyPI	All versions	`2.2.0rc0, 2.3.0rc0, 2.3.4, 2.4.3`
`tensorflow` PyPI	All versions	`2.1.4`
`tensorflow` PyPI	All versions	`2.1.4`
`tensorflow` PyPI	From `2.2.0`	`2.2.3`
`tensorflow` PyPI	From `2.2.0`	`2.2.3`

22 more packages

`tensorflow` PyPI	From `2.3.0`	`2.3.3`
`tensorflow` PyPI	From `2.3.0`	`2.3.3`
`tensorflow` PyPI	From `2.4.0`	`2.4.2`
`tensorflow` PyPI	From `2.4.0`	`2.4.2`
`tensorflow-cpu` PyPI	All versions	`2.2.0rc0, 2.3.0rc0, 2.3.4, 2.4.3`
`tensorflow-cpu` PyPI	All versions	`2.1.4`
`tensorflow-cpu` PyPI	All versions	`2.1.4`
`tensorflow-cpu` PyPI	From `2.2.0`	`2.2.3`
`tensorflow-cpu` PyPI	From `2.2.0`	`2.2.3`
`tensorflow-cpu` PyPI	From `2.3.0`	`2.3.3`
`tensorflow-cpu` PyPI	From `2.3.0`	`2.3.3`
`tensorflow-cpu` PyPI	From `2.4.0`	`2.4.2`
`tensorflow-cpu` PyPI	From `2.4.0`	`2.4.2`
`tensorflow-gpu` PyPI	All versions	`2.2.0rc0, 2.3.0rc0, 2.3.4, 2.4.3`
`tensorflow-gpu` PyPI	All versions	`2.1.4`
`tensorflow-gpu` PyPI	All versions	`2.1.4`
`tensorflow-gpu` PyPI	From `2.2.0`	`2.2.3`
`tensorflow-gpu` PyPI	From `2.2.0`	`2.2.3`
`tensorflow-gpu` PyPI	From `2.3.0`	`2.3.3`
`tensorflow-gpu` PyPI	From `2.3.0`	`2.3.3`
`tensorflow-gpu` PyPI	From `2.4.0`	`2.4.2`
`tensorflow-gpu` PyPI	From `2.4.0`	`2.4.2`

Products include Google Tensorflow.

How do I fix CVE-2021-29566?

Upgrade tensorflow to a fixed version for your release line: 2.1.4, 2.2.3, 2.3.3 or 2.4.2.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-29566 being exploited?

There is no known exploitation of CVE-2021-29566 in the wild and no public exploit code.

All Google Tensorflow vulnerabilities

Sources

Also known as BIT-tensorflow-2021-29566, GHSA-pvrc-hg3f-58r6, PYSEC-2021-203, PYSEC-2021-494, PYSEC-2021-692.