CVE-2021-41198 : Security Advisory and Response

TensorFlow is an open-source platform for machine learning. In affected versions, calling

tf.tile

with a large input argument results in a process crash due to an overflow. This issue affects versions >= 2.6.0, < 2.6.1; >= 2.5.0, < 2.5.2; and < 2.4.4. The impact includes a high availability impact with a CVSS base score of 5.5.

Understanding CVE-2021-41198

In this CVE, the

tf.tile

function in TensorFlow triggers a process crash when tiled with a large tensor due to an overflow condition.

What is CVE-2021-41198?

TensorFlow experiences a crash if

tf.tile

is used with a large input, causing an overflow due to an element count exceeding

int64_t

range.

The Impact of CVE-2021-41198

CVSS Score: 5.5 (Medium Severity)
Attack Vector: Local
Privileges Required: Low
User Interaction: None
Availability Impact: High
Integrity Impact: None
Confidentiality Impact: None
Scope: Unchanged

Technical Details of CVE-2021-41198

This section covers the technical aspects of the vulnerability.

Vulnerability Description

The issue arises in TensorFlow when

tf.tile

is used with a large input, leading to a process crash from an overflow detected by a

CHECK

statement.

Affected Systems and Versions

Versions >= 2.6.0, < 2.6.1
Versions >= 2.5.0, < 2.5.2
Version < 2.4.4

Exploitation Mechanism

Calling

tf.tile

excessively with a significant input tensor triggers the overflow, detected by a

CHECK

statement, resulting in a process crash.

Mitigation and Prevention

Suggestions to mitigate the impact and prevent future occurrences.

Immediate Steps to Take

Update TensorFlow to version 2.7.0 when available.
Apply patches/cherry-picks on TensorFlow 2.6.1, 2.5.2, and 2.4.4.

Long-Term Security Practices

Regularly check for TensorFlow updates and apply them promptly.
Ensure input data within TensorFlow functions stays within safe ranges.

Patching and Updates

The fix will be included in TensorFlow 2.7.0.
Apply patches/cherry-picks on TensorFlow 2.6.1, 2.5.2, and 2.4.4 to address the vulnerability.