CVE-2021-29538
Division by zero in `Conv2DBackpropFilter`
Description
TensorFlow is an end-to-end open source platform for machine learning. An attacker can cause a division by zero to occur in `Conv2DBackpropFilter`. This is because the implementation(https://github.com/tensorflow/tensorflow/blob/1b0296c3b8dd9bd948f924aa8cd62f87dbb7c3da/tensorflow/core/kernels/conv_grad_filter_ops.cc#L513-L522) computes a divisor based on user provided data (i.e., the shape of the tensors given as arguments). If all shapes are empty then `work_unit_size` is 0. Since there is no check for this case before division, this results in a runtime exception, with potential to be abused for a denial of service. 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.
How to fix CVE-2021-29538
To remediate CVE-2021-29538, upgrade the affected package to a fixed version below.
- —upgrade to 2.1.4 or later
- —upgrade to 2.1.4 or later
- —upgrade to c570e2ecfc822941335ad48f6e10df4e21f11c96 or later
- —upgrade to c570e2ecfc822941335ad48f6e10df4e21f11c96 or later
- —upgrade to 2.1.4 or later
- —upgrade to c570e2ecfc822941335ad48f6e10df4e21f11c96 or later
- —upgrade to 2.1.4 or later
Is CVE-2021-29538 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (7)
- from 0, < 2.1.4, >= 2.2.0, < 2.2.3, >= 2.3.0, < 2.3.3, >= 2.4.0, < 2.4.2
- from 0, < 2.1.4
- from 0, < c570e2ecfc822941335ad48f6e10df4e21f11c96 | from 0, < 2.2.0rc0, >= 2.2.0, < 2.3.0rc0, >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
- from 0, < c570e2ecfc822941335ad48f6e10df4e21f11c96 | from 0, < 2.2.0rc0, >= 2.2.0, < 2.3.0rc0, >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
- from 0, < 2.1.4
- from 0, < c570e2ecfc822941335ad48f6e10df4e21f11c96 | from 0, < 2.2.0rc0, >= 2.2.0, < 2.3.0rc0, >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
- from 0, < 2.1.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | LOW2.5 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L |