CVE-2021-29545: Denial of Service in TensorFlow
Summary
CVE-2021-29545: TensorFlow is an end-to-end open source platform for machine learning. Affects tensorflow across 5 version ranges.
< 1e922ccdf6bf46a3a52641f99fd47d54c1decd13
>= 2.2.0, < 2.3.0rc0
< 2.2.0rc0
>= 2.3.0, < 2.3.4
>= 2.4.0, < 2.4.3
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-2021-29545 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 community resources that enable researchers and developers to build and deploy machine learning models. TensorFlow supports various operations, including converting sparse tensors to CSR Sparse matrices.
Vulnerability Detail
The vulnerability (CVE-2021-29545) in TensorFlow allows an attacker to trigger a denial of service attack. The issue arises when converting sparse tensors to CSR Sparse matrices. The implementation of this conversion process involves accessing an element of an array allocated on the heap. However, there is a flaw in the implementation that leads to a double redirection, resulting in writing outside the bounds of the heap-allocated data. This can be exploited by an attacker by providing a specific value that causes the program to write outside the allocated memory. The impact of this vulnerability can lead to a crash or freeze of the TensorFlow application, causing a denial of service.
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"
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 mentioned for this vulnerability. However, users can mitigate the risk by updating to the patched versions of TensorFlow as mentioned in the 'how_to_fix' section.
Conclusion
The vulnerability in TensorFlow (CVE-2021-29545) allows an attacker to trigger a denial of service attack by exploiting a flaw in the conversion of sparse tensors to CSR Sparse matrices. The impact of this vulnerability can lead to a crash or freeze of the TensorFlow application. Users are advised to update their TensorFlow installations to the patched versions once they are released. Regularly updating TensorFlow is recommended to ensure the latest security fixes are applied. For further support on 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 set of tools and libraries for building and deploying machine learning models.
The vulnerability can be exploited by an attacker to trigger a denial of service attack, causing the TensorFlow application to crash or freeze.
The vulnerability will be fixed in TensorFlow 2.5.0. Users are advised to update their TensorFlow installations to the patched versions once they are released.
Yes, older versions of TensorFlow including 2.4.2, 2.3.3, 2.2.3, and 2.1.4 are also affected by this vulnerability. The fix will be backported to these versions.
There is no specific workaround mentioned for this vulnerability. It is recommended to update to the patched versions of TensorFlow.
References
Related vulnerabilities
Recent vulnerabilities recorded for tensorflow.
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