CVE-2021-29549: TensorFlow - Division by Zero Denial of Service
Summary
CVE-2021-29549: TensorFlow is an end-to-end open source platform for machine learning. Affects tensorflow across 5 version ranges.
>= 2.2.0, < 2.3.0rc0
< 2.2.0rc0
>= 2.3.0, < 2.3.4
>= 2.4.0, < 2.4.3
< 744009c9e5cc5d0447f0dc39d055f917e1fd9e16
Fixed in 4 releases; the minimum fixed version depends on the release line you run. How to fix ↓
Also tracked for
- tensorflow · Bitnami
- tensorflow-cpu · PyPI
- tensorflow-gpu · PyPI
The same CVE-2021-29549 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
TensorFlow is an end-to-end open source platform for machine learning. It provides a comprehensive ecosystem of tools, libraries, and resources for developing and deploying machine learning models. TensorFlow is widely used in various industries and research domains for tasks such as image recognition, natural language processing, and recommendation systems. However, a vulnerability has been discovered in TensorFlow that can lead to a division by zero error and denial of service.
Vulnerability Detail
The vulnerability exists in the tf.raw_ops.QuantizedBatchNormWithGlobalNormalization function of TensorFlow. The implementation of this function performs a modulo operation without validating that the divisor is not zero. By manipulating the input shapes, an attacker can trigger scenarios where the divisor becomes zero, causing a runtime division by zero error. This error can lead to a denial of service, as the affected operation will fail and potentially crash the application. The vulnerability has been assigned the identifier CVE-2021-29549.
How To Fix
Latest published version: 2.21.0 as of 22 Oct 2026
pip install --upgrade "tensorflow==2.21.0"
Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.
If you can't move to the latest
The minimum fixed version depends on the release line you run.
-
< 2.2.0rc02.2.0rc0pip install --upgrade "tensorflow==2.2.0rc0" -
>= 2.2.0, < 2.3.0rc02.3.0rc0pip install --upgrade "tensorflow==2.3.0rc0" -
>= 2.3.0, < 2.3.42.3.4pip install --upgrade "tensorflow==2.3.4" -
>= 2.4.0, < 2.4.32.4.3pip install --upgrade "tensorflow==2.4.3"
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Workaround
As a temporary workaround, you can modify the affected code to include a validation check for the divisor before performing the modulo operation. Here is an example of how you can add the validation check:
def quantized_batch_norm_with_global_normalization(divisor):
if divisor == 0:
# Handle the zero divisor case
return
# Perform the modulo operation
result = tf.raw_ops.QuantizedBatchNormWithGlobalNormalization(divisor)
return result
Conclusion
The division by zero denial of service vulnerability in TensorFlow can be mitigated by upgrading to the latest patched version. It is recommended to promptly update your TensorFlow installation to ensure the security and stability of your machine learning applications. For further assistance and support in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for tensorflow →
FAQ
TensorFlow is an open source platform for machine learning that provides a comprehensive ecosystem of tools and resources.
The vulnerability can lead to a runtime division by zero error and denial of service in TensorFlow applications.
The vulnerability affects TensorFlow versions 2.1.4, 2.2.3, 2.3.3, 2.4.2, and versions prior to 2.5.0.
You can fix this vulnerability by upgrading to the latest patched version of TensorFlow.
Yes, you can apply a temporary workaround by adding a validation check for the divisor in the affected code.
References
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