CVE-2021-37686 Infinite loop in TensorFlow Lite
An attacker can cause a denial of service via an infinite loop in TensorFlow Lite by crafting a malicious model with specific strided slice parameters.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-37686?
CVE-2021-37686 is a medium-severity denial of service vulnerability in Google Tensorflow, published on 12 Aug 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
TensorFlow is an end-to-end open source platform for machine learning. In affected versions the strided slice implementation in TFLite has a logic bug which can allow an attacker to trigger an infinite loop. This arises from newly introduced support for [ellipsis in axis definition](https://github.com/tensorflow/tensorflow/blob/149562d49faa709ea80df1d99fc41d005b81082a/tensorflow/lite/kernels/strided_slice.cc#L103-L122). An attacker can craft a model such that `ellipsis_end_idx` is smaller than `i` (e.g., always negative). In this case, the inner loop does not increase `i` and the `continue` statement causes execution to skip over the preincrement at the end of the outer loop. We have patched the issue in GitHub commit dfa22b348b70bb89d6d6ec0ff53973bacb4f4695. TensorFlow 2.6.0 is the only affected version.
Weakness: CWE-835
Which versions are affected by CVE-2021-37686?
10 open source packages ship an affected version, including tensorflow, tensorflow-cpu and tensorflow-gpu. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
tensorflow Bitnami | From 2.3.0 | 2.3.4, 2.4.3, 2.5.1 |
tensorflow PyPI | From 2.3.0 | 2.3.4, 2.4.3 |
tensorflow PyPI | From 2.6.0rc0 | 2.6.0rc2 |
tensorflow PyPI | From 2.6.0rc0 | 2.6.0rc2 |
tensorflow-cpu PyPI | From 2.3.0 | 2.3.4, 2.4.3 |
tensorflow-cpu PyPI | From 2.6.0rc0 | 2.6.0rc2 |
4 more packages
tensorflow-cpu PyPI | From 2.6.0rc0 | 2.6.0rc2 |
tensorflow-gpu PyPI | From 2.3.0 | 2.3.4, 2.4.3 |
tensorflow-gpu PyPI | From 2.6.0rc0 | 2.6.0rc2 |
tensorflow-gpu PyPI | From 2.6.0rc0 | 2.6.0rc2 |
Products include Google Tensorflow.
How do I fix CVE-2021-37686?
Upgrade tensorflow to a fixed version for your release line: 2.3.4, 2.4.3, 2.5.1 or 2.6.0rc2.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-37686 being exploited?
There is no known exploitation of CVE-2021-37686 in the wild and no public exploit code.
Other vulnerabilities in Google Tensorflow
- CVE-2023-25668 TensorFlow vulnerable to heap out-of-buffer read in the QuantizeAndDequantize operation
- CVE-2018-7575 Integer Overflow or Wraparound in Google TensorFlow
- CVE-2021-37678 Arbitrary code execution due to YAML deserialization
- CVE-2021-35958 Path traversal in n/a
- CVE-2020-15202 Integer truncation in Shard API usage
Sources
Also known as BIT-tensorflow-2021-37686, GHSA-mhhc-q96p-mfm9, PYSEC-2021-308, PYSEC-2021-599, PYSEC-2021-797.