CVE-2021-41219 Undefined behavior via `nullptr` reference binding in sparse matrix multiplication

High 7.8 Published Updated

Attackers can trigger undefined behavior and potential heap out-of-bounds access in TensorFlow's sparse matrix multiplication by providing zero or negative dimensions.

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-2021-41219?

CVE-2021-41219 is a high-severity vulnerability in Google Tensorflow, published on 5 Nov 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

TensorFlow is an open source platform for machine learning. In affected versions the code for sparse matrix multiplication is vulnerable to undefined behavior via binding a reference to `nullptr`. This occurs whenever the dimensions of `a` or `b` are 0 or less. In the case on one of these is 0, an empty output tensor should be allocated (to conserve the invariant that output tensors are always allocated when the operation is successful) but nothing should be written to it (that is, we should return early from the kernel implementation). Otherwise, attempts to write to this empty tensor would result in heap OOB access. The fix will be included in TensorFlow 2.7.0. We will also cherrypick this commit on TensorFlow 2.6.1, TensorFlow 2.5.2, and TensorFlow 2.4.4, as these are also affected and still in supported range.

Weakness: CWE-125, CWE-824

Which versions are affected by CVE-2021-41219?

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

PackageAffectedFixed in
tensorflow BitnamiAll versions2.4.4, 2.5.2, 2.6.1
tensorflow PyPIAll versions2.4.4, 2.5.2, 2.6.1, 2.7.0
tensorflow PyPIAll versions2.4.4
tensorflow PyPIAll versions2.4.4
tensorflow PyPIFrom 2.5.02.5.2
tensorflow PyPIFrom 2.5.02.5.2
16 more packages
tensorflow PyPIFrom 2.6.02.6.1
tensorflow PyPIFrom 2.6.02.6.1
tensorflow-cpu PyPIAll versions2.4.4, 2.5.2, 2.6.1, 2.7.0
tensorflow-cpu PyPIAll versions2.4.4
tensorflow-cpu PyPIAll versions2.4.4
tensorflow-cpu PyPIFrom 2.5.02.5.2
tensorflow-cpu PyPIFrom 2.5.02.5.2
tensorflow-cpu PyPIFrom 2.6.02.6.1
tensorflow-cpu PyPIFrom 2.6.02.6.1
tensorflow-gpu PyPIAll versions2.4.4, 2.5.2, 2.6.1, 2.7.0
tensorflow-gpu PyPIAll versions2.4.4
tensorflow-gpu PyPIAll versions2.4.4
tensorflow-gpu PyPIFrom 2.5.02.5.2
tensorflow-gpu PyPIFrom 2.5.02.5.2
tensorflow-gpu PyPIFrom 2.6.02.6.1
tensorflow-gpu PyPIFrom 2.6.02.6.1

Products include Google Tensorflow.

How do I fix CVE-2021-41219?

Upgrade tensorflow to a fixed version for your release line: 2.4.4, 2.5.2, 2.6.1 or 2.7.0.

Is CVE-2021-41219 being exploited?

There is no known exploitation of CVE-2021-41219 in the wild and no public exploit code.

All Google Tensorflow vulnerabilities

Sources

Also known as BIT-tensorflow-2021-41219, GHSA-4f99-p9c2-3j8x, PYSEC-2021-411, PYSEC-2021-628, PYSEC-2021-826.

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