What’s Vulnerable › Vulnerabilities

CVE-2021-29544: CHECK-fail in `QuantizeAndDequantizeV4Grad`

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-05-14 · updated 2026-06-17
• Weakness: CWE-754

Description

TensorFlow is an end-to-end open source platform for machine learning. An attacker can trigger a denial of service via a `CHECK`-fail in `tf.raw_ops.QuantizeAndDequantizeV4Grad`. This is because the implementation does not validate the rank of the `input_*` tensors. In turn, this results in the tensors being passes as they are to `QuantizeAndDequantizePerChannelGradientImpl`. However, the `vec<T>` method, requires the rank to 1 and triggers a `CHECK` failure otherwise. The fix will be included in TensorFlow 2.5.0. We will also cherrypick this commit on TensorFlow 2.4.2 as this is the only other affected version.

Affected products

• tensorflow: from 2.4.0 before 2.4.2 — fixed in 2.4.2

How to fix

Upgrade to a fixed version: tensorflow 2.4.2. Check the vendor advisory for mitigations.

References

• https://github.com/tensorflow/tensorflow/blob/95078c145b5a7a43ee046144005f733092756ab5/tensorflow/core/kernels/quantize_and_dequantize_op.cc#L162-L163
• https://github.com/tensorflow/tensorflow/blob/95078c145b5a7a43ee046144005f733092756ab5/tensorflow/core/kernels/quantize_and_dequantize_op.h#L295-L306
• https://github.com/tensorflow/tensorflow/commit/20431e9044cf2ad3c0323c34888b192f3289af6b
• https://github.com/tensorflow/tensorflow/security/advisories/GHSA-6g85-3hm8-83f9
• https://github.com/tensorflow/tensorflow/commit/20431e9044cf2ad3c0323c34888b192f3289af6b
• https://github.com/tensorflow/tensorflow/security/advisories/GHSA-6g85-3hm8-83f9

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