# CVE-2021-37659: Out of bounds read via null pointer dereference in TensorFlow > An attacker can trigger undefined behavior and heap out-of-bounds reads in TensorFlow binary operations by providing mismatched input sizes, potentially causing crashes or data leaks. - **Severity:** High 7.3 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H`) - **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:** Yes - **Published:** 12 Aug 2021 - **Updated:** 4 Aug 2024 - **Also known as:** BIT-tensorflow-2021-37659, GHSA-q3g3-h9r4-prrc, PYSEC-2021-281, PYSEC-2021-572, PYSEC-2021-770 ## What is CVE-2021-37659? CVE-2021-37659 is a high-severity 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 an attacker can cause undefined behavior via binding a reference to null pointer in all binary cwise operations that don't require broadcasting (e.g., gradients of binary cwise operations). The [implementation](https://github.com/tensorflow/tensorflow/blob/84d053187cb80d975ef2b9684d4b61981bca0c41/tensorflow/core/kernels/cwise_ops_common.h#L264) assumes that the two inputs have exactly the same number of elements but does not check that. Hence, when the eigen functor executes it triggers heap OOB reads and undefined behavior due to binding to nullptr. We have patched the issue in GitHub commit 93f428fd1768df147171ed674fee1fc5ab8309ec. The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, as these are also affected and still in supported range. Weakness: CWE-476 (NULL Pointer Dereference), CWE-125 (Out-of-bounds Read) ## Which versions are affected by CVE-2021-37659? 22 open source packages ship an affected version, including tensorflow, tensorflow-cpu and tensorflow-gpu. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `tensorflow` | Bitnami | From 2.3.0 | 2.3.4, 2.4.3, 2.5.1 | | `tensorflow` | PyPI | All versions | 2.3.4 | | `tensorflow` | PyPI | All versions | 2.3.4 | | `tensorflow` | PyPI | From 2.3.0 | 2.3.4, 2.4.3 | | `tensorflow` | PyPI | From 2.4.0 | 2.4.3 | | `tensorflow` | PyPI | From 2.4.0 | 2.4.3 | | `tensorflow` | PyPI | From 2.5.0 | 2.5.1 | | `tensorflow` | PyPI | From 2.5.0 | 2.5.1 | | `tensorflow-cpu` | PyPI | All versions | 2.3.4 | | `tensorflow-cpu` | PyPI | All versions | 2.3.4 | | `tensorflow-cpu` | PyPI | From 2.3.0 | 2.3.4, 2.4.3 | | `tensorflow-cpu` | PyPI | From 2.4.0 | 2.4.3 | | `tensorflow-cpu` | PyPI | From 2.4.0 | 2.4.3 | | `tensorflow-cpu` | PyPI | From 2.5.0 | 2.5.1 | | `tensorflow-cpu` | PyPI | From 2.5.0 | 2.5.1 | | `tensorflow-gpu` | PyPI | All versions | 2.3.4 | | `tensorflow-gpu` | PyPI | All versions | 2.3.4 | | `tensorflow-gpu` | PyPI | From 2.3.0 | 2.3.4, 2.4.3 | | `tensorflow-gpu` | PyPI | From 2.4.0 | 2.4.3 | | `tensorflow-gpu` | PyPI | From 2.4.0 | 2.4.3 | | `tensorflow-gpu` | PyPI | From 2.5.0 | 2.5.1 | | `tensorflow-gpu` | PyPI | From 2.5.0 | 2.5.1 | Products: Google Tensorflow. ## How do I fix CVE-2021-37659? Upgrade tensorflow to a fixed version for your release line: 2.3.4, 2.4.3 or 2.5.1. ## Is CVE-2021-37659 being exploited? There is no known exploitation of CVE-2021-37659 in the wild and no public exploit code. ## Other vulnerabilities in Google Tensorflow - [CVE-2023-25668](https://insights.sbomify.com/CVE-2023-25668/): TensorFlow vulnerable to heap out-of-buffer read in the QuantizeAndDequantize operation (critical 9.8) - [CVE-2018-7575](https://insights.sbomify.com/CVE-2018-7575/): Integer Overflow or Wraparound in Google TensorFlow (critical 9.8) - [CVE-2021-37678](https://insights.sbomify.com/CVE-2021-37678/): Arbitrary code execution due to YAML deserialization (critical 9.3) - [CVE-2021-35958](https://insights.sbomify.com/CVE-2021-35958/): Path traversal in n/a (critical 9.1) - [CVE-2020-15202](https://insights.sbomify.com/CVE-2020-15202/): Integer truncation in Shard API usage (critical 9.0) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-37659 and fix it if it is affected. What it is: CVE-2021-37659 is a high-severity 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. Exploitation: There is no known exploitation of CVE-2021-37659 in the wild and no public exploit code. Affected packages and fixed versions: - tensorflow (Bitnami): affected from 2.3.0; fixed in 2.3.4, 2.4.3, 2.5.1 - tensorflow (PyPI): affected all versions; fixed in 2.3.4 - tensorflow (PyPI): affected all versions; fixed in 2.3.4 - tensorflow (PyPI): affected from 2.3.0; fixed in 2.3.4, 2.4.3 - tensorflow (PyPI): affected from 2.4.0; fixed in 2.4.3 - tensorflow (PyPI): affected from 2.4.0; fixed in 2.4.3 - tensorflow (PyPI): affected from 2.5.0; fixed in 2.5.1 - tensorflow (PyPI): affected from 2.5.0; fixed in 2.5.1 - tensorflow-cpu (PyPI): affected all versions; fixed in 2.3.4 - tensorflow-cpu (PyPI): affected all versions; fixed in 2.3.4 - tensorflow-cpu (PyPI): affected from 2.3.0; fixed in 2.3.4, 2.4.3 - tensorflow-cpu (PyPI): affected from 2.4.0; fixed in 2.4.3 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2021-37659/ (Markdown: https://insights.sbomify.com/CVE-2021-37659/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-37659 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-37659 - OSV: https://osv.dev/vulnerability/CVE-2021-37659 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-37659/ Summaries are generated and may contain mistakes; the official description above is the record.