CVE-2021-37686

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.

How to fix CVE-2021-37686

To remediate CVE-2021-37686, upgrade the affected package to a fixed version below.

—upgrade to 2.3.4 or later
—upgrade to 2.6.0rc2 or later
—upgrade to dfa22b348b70bb89d6d6ec0ff53973bacb4f4695 or later
—upgrade to dfa22b348b70bb89d6d6ec0ff53973bacb4f4695 or later
—upgrade to 2.6.0rc2 or later
—upgrade to dfa22b348b70bb89d6d6ec0ff53973bacb4f4695 or later
—upgrade to 2.6.0rc2 or later

Is CVE-2021-37686 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
>= 2.6.0rc0, < 2.6.0rc2
from 0, < dfa22b348b70bb89d6d6ec0ff53973bacb4f4695 | >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
from 0, < dfa22b348b70bb89d6d6ec0ff53973bacb4f4695 | >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
>= 2.6.0rc0, < 2.6.0rc2
from 0, < dfa22b348b70bb89d6d6ec0ff53973bacb4f4695 | >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
>= 2.6.0rc0, < 2.6.0rc2

CVSS scores

Source	Version	Severity	Vector
osv	CVSS 4.0	—	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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:N/I:N/A:H