CVE-2021-37690 : What You Need to Know

TensorFlow, an end-to-end open source platform for machine learning, was found to have a vulnerability in its shape inference functions. This vulnerability could lead to a use-after-free scenario and trigger a segmentation fault under specific conditions.

Understanding CVE-2021-37690

This CVE describes a flaw in TensorFlow that results in a use-after-free issue and potential segfaults when certain shape functions are executed, leading to memory corruption.

What is CVE-2021-37690?

In affected versions of TensorFlow, when running shape functions, specific functions can produce extra output information that may trigger a segmentation fault if accessed by upstream code. This issue arises from the handling of shapes and types within the inference context.

The Impact of CVE-2021-37690

The impact of this vulnerability is considered medium with a CVSS base score of 6.6. Although the attack complexity is low, the availability impact is high, potentially leading to denial of service.

Technical Details of CVE-2021-37690

The vulnerability in TensorFlow's shape inference functions stems from the improper handling of shape and type information, leading to memory corruption.

Vulnerability Description

The vulnerability allows for a use-after-free scenario where accessing shape information in specific conditions can cause a segmentation fault, potentially leading to denial of service.

Affected Systems and Versions

The vulnerability affects TensorFlow versions >= 2.5.0 and < 2.5.1, >= 2.4.0 and < 2.4.3, and versions < 2.3.4.

Exploitation Mechanism

By accessing specific shape information in affected TensorFlow versions, an attacker could exploit the vulnerability to trigger a segfault, causing a denial of service.

Mitigation and Prevention

It is crucial to take immediate steps to mitigate the risk posed by CVE-2021-37690 and implement long-term security practices to prevent similar vulnerabilities.

Immediate Steps to Take

Users should update to the patched versions of TensorFlow (2.5.1, 2.4.3, 2.3.4, or later) to address the vulnerability and prevent potential exploitation.

Long-Term Security Practices

Regularly updating software and libraries, monitoring security advisories, and conducting security assessments can help prevent and detect vulnerabilities like CVE-2021-37690.

Patching and Updates

The issue has been addressed in TensorFlow 2.6.0, and patches are available for TensorFlow 2.5.1, 2.4.3, and 2.3.4. Users are advised to apply these patches to secure their systems.