CVE-2021-29552

Description

TensorFlow is an end-to-end open source platform for machine learning. An attacker can cause a denial of service by controlling the values of `num_segments` tensor argument for `UnsortedSegmentJoin`. This is because the implementation(https://github.com/tensorflow/tensorflow/blob/a2a607db15c7cd01d754d37e5448d72a13491bdb/tensorflow/core/kernels/unsorted_segment_join_op.cc#L92-L93) assumes that the `num_segments` tensor is a valid scalar. Since the tensor is empty the `CHECK` involved in `.scalar<T>()()` that checks that the number of elements is exactly 1 will be invalidated and this would result in process termination. The fix will be included in TensorFlow 2.5.0. We will also cherrypick this commit on TensorFlow 2.4.2, TensorFlow 2.3.3, TensorFlow 2.2.3 and TensorFlow 2.1.4, as these are also affected and still in supported range.

How to fix CVE-2021-29552

To remediate CVE-2021-29552, upgrade the affected package to a fixed version below.

—upgrade to 2.1.4 or later
—upgrade to 2.1.4 or later
—upgrade to 704866eabe03a9aeda044ec91a8d0c83fc1ebdbe or later
—upgrade to 704866eabe03a9aeda044ec91a8d0c83fc1ebdbe or later
—upgrade to 2.1.4 or later
—upgrade to 704866eabe03a9aeda044ec91a8d0c83fc1ebdbe or later
—upgrade to 2.1.4 or later

Is CVE-2021-29552 being exploited?

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

Affected packages (7)

from 0, < 2.1.4, >= 2.2.0, < 2.2.3, >= 2.3.0, < 2.3.3, >= 2.4.0, < 2.4.2
from 0, < 2.1.4
from 0, < 704866eabe03a9aeda044ec91a8d0c83fc1ebdbe | from 0, < 2.2.0rc0, >= 2.2.0, < 2.3.0rc0, >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
from 0, < 704866eabe03a9aeda044ec91a8d0c83fc1ebdbe | from 0, < 2.2.0rc0, >= 2.2.0, < 2.3.0rc0, >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
from 0, < 2.1.4
from 0, < 704866eabe03a9aeda044ec91a8d0c83fc1ebdbe | from 0, < 2.2.0rc0, >= 2.2.0, < 2.3.0rc0, >= 2.3.0, < 2.3.4, >= 2.4.0, < 2.4.3
from 0, < 2.1.4

CVSS scores

Source	Version	Severity	Vector
osv	CVSS 4.0	—	CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
osv	CVSS 3.1	LOW2.5	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L