CVE-2021-29543: Denial of Service in TensorFlow
Summary
CVE-2021-29543: TensorFlow is an end-to-end open source platform for machine learning. Affects tensorflow-cpu 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
< ea3b43e98c32c97b35d52b4c66f9107452ca8fb2
Fixed in 4 releases; the minimum fixed version depends on the release line you run. How to fix ↓
Also tracked for
- tensorflow · Bitnami
- tensorflow · PyPI
- tensorflow · PyPI
- tensorflow-gpu · PyPI
The same CVE-2021-29543 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 denial of service attack.
Vulnerability Detail
The vulnerability, identified as CVE-2021-29543, resides in the tf.raw_ops.CTCGreedyDecoder function of TensorFlow. An attacker can trigger a denial of service by exploiting a CHECK-fail condition in the implementation of this function. The vulnerable code contains a CHECK_LT statement that checks certain invariants. If this condition is false, the program aborts abruptly instead of returning a proper error message to the user. This abnormal termination can be exploited by an attacker to cause a denial of service, disrupting the availability of the TensorFlow application. The issue has been addressed in TensorFlow 2.5.0, and patches have been released for earlier versions as well.
How To Fix
Latest published version: 2.21.0 as of 22 Oct 2026
pip install --upgrade "tensorflow-cpu==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-cpu==2.2.0rc0" -
>= 2.2.0, < 2.3.0rc02.3.0rc0pip install --upgrade "tensorflow-cpu==2.3.0rc0" -
>= 2.3.0, < 2.3.42.3.4pip install --upgrade "tensorflow-cpu==2.3.4" -
>= 2.4.0, < 2.4.32.4.3pip install --upgrade "tensorflow-cpu==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
There is no specific workaround available for this vulnerability. The recommended approach is to update TensorFlow to the patched version.
Conclusion
In conclusion, a denial of service vulnerability has been discovered in TensorFlow that can be exploited by an attacker. It is crucial to update TensorFlow to the latest patched version or apply the appropriate patches for earlier versions to mitigate the risk. For further support and assistance in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for tensorflow-cpu →
FAQ
TensorFlow is an open source platform for machine learning that provides a comprehensive set of tools and libraries for developing and deploying machine learning models.
The vulnerability allows an attacker to trigger a denial of service attack, leading to the unavailability of the TensorFlow application.
To fix this vulnerability, update TensorFlow to version 2.5.0 or apply the appropriate patches for earlier versions.
No, the vulnerability affects TensorFlow versions 2.1.4 and above. Earlier versions are not affected.
No, there is no specific workaround available. Updating to the patched version is the recommended solution.
References
Related vulnerabilities
Recent vulnerabilities recorded for tensorflow-cpu.
