CVE-2021-29521

Public Exploit
Segfault in SparseCountSparseOutput

Description

TensorFlow is an end-to-end open source platform for machine learning. Specifying a negative dense shape in `tf.raw_ops.SparseCountSparseOutput` results in a segmentation fault being thrown out from the standard library as `std::vector` invariants are broken. This is because the implementation(https://github.com/tensorflow/tensorflow/blob/8f7b60ee8c0206a2c99802e3a4d1bb55d2bc0624/tensorflow/core/kernels/count_ops.cc#L199-L213) assumes the first element of the dense shape is always positive and uses it to initialize a `BatchedMap<T>` (i.e., `std::vector<absl::flat_hash_map<int64,T>>`(https://github.com/tensorflow/tensorflow/blob/8f7b60ee8c0206a2c99802e3a4d1bb55d2bc0624/tensorflow/core/kernels/count_ops.cc#L27)) data structure. If the `shape` tensor has more than one element, `num_batches` is the first value in `shape`. Ensuring that the `dense_shape` argument is a valid tensor shape (that is, all elements are non-negative) solves this issue. The fix will be included in TensorFlow 2.5.0. We will also cherrypick this commit on TensorFlow 2.4.2 and TensorFlow 2.3.3.

Category

2.5
CVSS
Severity: Low
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.01%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: tensorflow tensorflow
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2021-29521?
CVE-2021-29521 has been scored as a low severity vulnerability.
How to fix CVE-2021-29521?
To fix CVE-2021-29521, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-29521 being actively exploited in the wild?
It is possible that CVE-2021-29521 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-29521?
CVE-2021-29521 affects tensorflow tensorflow.
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