CVE-2021-37685

Description

TensorFlow is an end-to-end open source platform for machine learning. In affected versions TFLite's [`expand_dims.cc`](https://github.com/tensorflow/tensorflow/blob/149562d49faa709ea80df1d99fc41d005b81082a/tensorflow/lite/kernels/expand_dims.cc#L36-L50) contains a vulnerability which allows reading one element outside of bounds of heap allocated data. If `axis` is a large negative value (e.g., `-100000`), then after the first `if` it would still be negative. The check following the `if` statement will pass and the `for` loop would read one element before the start of `input_dims.data` (when `i = 0`). We have patched the issue in GitHub commit d94ffe08a65400f898241c0374e9edc6fa8ed257. 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.

How to fix CVE-2021-37685

To remediate CVE-2021-37685, upgrade the affected package to a fixed version below.

—upgrade to 2.3.4 or later
—upgrade to 2.3.4 or later
—upgrade to d94ffe08a65400f898241c0374e9edc6fa8ed257 or later
—upgrade to d94ffe08a65400f898241c0374e9edc6fa8ed257 or later
—upgrade to 2.3.4 or later
—upgrade to d94ffe08a65400f898241c0374e9edc6fa8ed257 or later
—upgrade to 2.3.4 or later

Is CVE-2021-37685 being exploited?

Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.

Affected packages (7)

>= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3, >= 2.5.0, < 2.5.1
from 0, < 2.3.4
from 0, < d94ffe08a65400f898241c0374e9edc6fa8ed257 | >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
from 0, < d94ffe08a65400f898241c0374e9edc6fa8ed257 | >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
from 0, < 2.3.4
from 0, < d94ffe08a65400f898241c0374e9edc6fa8ed257 | >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
from 0, < 2.3.4

CVSS scores

Source	Version	Severity	Vector
osv	CVSS 4.0	—	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
osv	CVSS 3.1	MEDIUM5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N