CVE-2021-29593: Division by zero in TFLite's implementation of `BatchToSpaceNd`
Impact The implementation of the BatchToSpaceNd TFLite operator is vulnerable to a division by zero error:
cc TFLITEENSUREEQ(context, outputbatchsize % blockshape[dim], 0); outputbatchsize = outputbatchsize / blockshape[dim];
An attacker can craft a model such that one dimension of the block input is 0. Hence, the corresponding value in blockshape is 0.
Patches We have patched the issue in GitHub commit 2c74674348a4708ced58ad6eb1b23354df8ee044.
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.
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. The implementation of the BatchToSpaceNd TFLite operator is vulnerable to a division by zero error(https://github.com/tensorflow/tensorflow/blob/b5ed552fe55895aee8bd8b191f744a069957d18d/tensorflow/lite/kernels/batchtospacend.cc#L81-L82). An attacker can craft a model such that one dimension of the block input is 0. Hence, the corresponding value in blockshape is 0. 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.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2021-29593?
CVE-2021-29593 has a medium severity due to the potential for a denial of service condition from a division by zero error.
What software versions are affected by CVE-2021-29593?
CVE-2021-29593 affects TensorFlow versions up to 2.1.4 and between 2.2.0 to 2.4.2.
How do I fix CVE-2021-29593?
To fix CVE-2021-29593, upgrade to TensorFlow version 2.4.2 or higher.
Can CVE-2021-29593 cause application crashes?
Yes, CVE-2021-29593 can cause application crashes due to the division by zero vulnerability.
Is CVE-2021-29593 a known issue with TensorFlow?
Yes, CVE-2021-29593 is a known issue that has been documented in TensorFlow's security advisories.