CVE-2021-29524: 
Python vulnerability analysis and mitigation

TensorFlow, an end-to-end open source platform for machine learning, was found to contain a division by zero vulnerability (CVE-2021-29524) in the Conv2DBackpropFilter operation. The vulnerability was discovered on May 14, 2021, affecting TensorFlow versions prior to 2.5.0, including versions 2.4.2, 2.3.3, 2.2.3, and 2.1.4 (TF Advisory).

The vulnerability exists in the implementation of Conv2DBackpropFilter where a modulus operation is performed with a divisor controlled by the caller. The issue occurs because the implementation does not properly validate the filter depth before performing the division operation. When the filtershape.dimsize(num_dims - 2) parameter is zero, it leads to a division by zero condition (TF Commit). The vulnerability has been assigned a CVSS score of 5.5 MEDIUM (NVD).

The vulnerability can be exploited by an attacker to trigger a division by zero error, which could lead to a denial of service condition in applications using the affected TensorFlow versions. The impact is considered low severity due to the specific conditions required for exploitation (TF Advisory).

The vulnerability has been patched in TensorFlow 2.5.0. The fix has also been backported to versions 2.4.2, 2.3.3, 2.2.3, and 2.1.4. Users are advised to upgrade to these patched versions. The fix includes adding validation to ensure the filter depth is strictly greater than zero before performing the division operation (TF Advisory).