CVE-2021-29549: TensorFlow - Division by Zero Denial of Service

tensorflow Updated 02 Oct 2025

Summary

14/05/2021
Yes i
Low
2.5

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

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.

Free scan

Check if this vulnerability affects your application

Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.

Check my app free

No signup required · Results in about 60 seconds

Sponsored Devnack Your last release was probably never penetration tested Manual testing by engineers who build software, not an auditor's checklist. Trusted by teams at Swift and Google Talk to Devnack

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.

  • < 2.2.0rc0 2.2.0rc0
    pip install --upgrade "tensorflow==2.2.0rc0"
  • >= 2.2.0, < 2.3.0rc0 2.3.0rc0
    pip install --upgrade "tensorflow==2.3.0rc0"
  • >= 2.3.0, < 2.3.4 2.3.4
    pip install --upgrade "tensorflow==2.3.4"
  • >= 2.4.0, < 2.4.3 2.4.3
    pip install --upgrade "tensorflow==2.4.3"

Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →

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 →

Share this vulnerability

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.

Related vulnerabilities

Recent vulnerabilities recorded for tensorflow.

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.

  • < 2.2.0rc0 2.2.0rc0
    pip install --upgrade "tensorflow==2.2.0rc0"
  • >= 2.2.0, < 2.3.0rc0 2.3.0rc0
    pip install --upgrade "tensorflow==2.3.0rc0"
  • >= 2.3.0, < 2.3.4 2.3.4
    pip install --upgrade "tensorflow==2.3.4"
  • >= 2.4.0, < 2.4.3 2.4.3
    pip install --upgrade "tensorflow==2.4.3"

Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →

Subscribe to Vulert on Telegram
Daily digest of new CVEs, critical and high severity, affected packages and fixes — plus a weekly roundup.
Join the channel →
Help improve this record
Report an issue or send feedback