CVE-2021-37667: Reference binding to nullptr in unicode encoding in TensorFlow
Impact An attacker can cause undefined behavior via binding a reference to null pointer in tf.rawops.UnicodeEncode:
python import tensorflow as tf from tensorflow.python.ops import genstringops
genstringops.unicodeencode( inputvalues=[], inputsplits=[], outputencoding='UTF-8', errors='ignore', replacementchar='a')
The implementation reads the first dimension of the inputsplits tensor before validating that this tensor is not empty:
cc const Tensor& inputsplits = context->input(1); const auto inputsplitsflat = inputsplits.flat<SPLITSTYPE>(); TensorShape outputshape({inputsplits.dimsize(0) - 1});
Patches We have patched the issue in GitHub commit 2e0ee46f1a47675152d3d865797a18358881d7a6.
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 members of the Aivul Team from Qihoo 360.
Other sources
TensorFlow is an end-to-end open source platform for machine learning. In affected versions an attacker can cause undefined behavior via binding a reference to null pointer in tf.rawops.UnicodeEncode. The implementation reads the first dimension of the inputsplits tensor before validating that this tensor is not empty. We have patched the issue in GitHub commit 2e0ee46f1a47675152d3d865797a18358881d7a6. 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
pip/tensorflow-gputo a version that resolves this vulnerability.Fixed in 2.5.1 - Upgrade
Upgrade
pip/tensorflow-gputo a version that resolves this vulnerability.Fixed in 2.4.3 - Upgrade
Upgrade
pip/tensorflow-gputo a version that resolves this vulnerability.Fixed in 2.3.4 - Upgrade
Upgrade
pip/tensorflow-cputo a version that resolves this vulnerability.Fixed in 2.5.1 - Upgrade
Upgrade
pip/tensorflow-cputo a version that resolves this vulnerability.Fixed in 2.4.3 - Upgrade
Upgrade
pip/tensorflow-cputo a version that resolves this vulnerability.Fixed in 2.3.4 - Upgrade
Upgrade
pip/tensorflowto a version that resolves this vulnerability.Fixed in 2.5.1 - Upgrade
Upgrade
pip/tensorflowto a version that resolves this vulnerability.Fixed in 2.4.3 - Upgrade
Upgrade
pip/tensorflowto a version that resolves this vulnerability.Fixed in 2.3.4 - Upgrade
Upgrade
tensorflowto a version that resolves this vulnerability.Patch 2e0ee46f1a47675152d3d865797a18358881d7a6 - Upgrade
Upgrade
tensorflowto a version that resolves this vulnerability.Fixed in 2.6.0 - Upgrade
Upgrade
tensorflowto a version that resolves this vulnerability.Fixed in 2.5.1 - Upgrade
Upgrade
tensorflowto a version that resolves this vulnerability.Fixed in 2.4.3 - Upgrade
Upgrade
tensorflowto a version that resolves this vulnerability.Fixed in 2.3.4
Event History
Frequently Asked Questions
What is CVE-2021-37667?
CVE-2021-37667 is a vulnerability in TensorFlow that allows an attacker to cause undefined behavior.
How does the vulnerability in TensorFlow occur?
The vulnerability in TensorFlow occurs when an attacker binds a reference to a null pointer in `tf.raw_ops.UnicodeEncode`.
What is the severity of CVE-2021-37667?
CVE-2021-37667 has a severity rating of 7.8 (high).
Which versions of TensorFlow are affected by CVE-2021-37667?
Versions 2.3.0 to 2.3.4, 2.4.0 to 2.4.3, 2.5.0, and 2.6.0-rc0 to 2.6.0-rc2 of TensorFlow are affected by CVE-2021-37667.
How can I fix the vulnerability in TensorFlow?
To fix the vulnerability in TensorFlow, update to a version that is not affected by CVE-2021-37667.