CVE-2021-29581 Explained : Impact and Mitigation

A vulnerability has been identified in TensorFlow that allows an attacker to trigger denial of service via segmentation faults. This vulnerability is tracked as CVE-2021-29581.

Understanding CVE-2021-29581

This section provides insights into the impact, technical details, and mitigation strategies related to the vulnerability.

What is CVE-2021-29581?

TensorFlow, an open-source machine learning platform, is affected by a flaw in

tf.raw_ops.CTCBeamSearchDecoder

. The vulnerability arises due to a lack of validation, enabling an attacker to exploit this issue for denial of service by causing segmentation faults.

The Impact of CVE-2021-29581

The vulnerability exposes systems running vulnerable versions of TensorFlow to potential denial of service attacks. By exploiting the flaw, an attacker can cause the application to crash, leading to service disruption.

Technical Details of CVE-2021-29581

Below are the technical aspects of the CVE, outlining the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability in

tf.raw_ops.CTCBeamSearchDecoder

fails to validate cases when the input tensor is empty, allowing the attacker to induce segmentation faults and trigger denial of service.

Affected Systems and Versions

The vulnerability impacts TensorFlow versions < 2.1.4, >= 2.2.0, < 2.2.3, >= 2.3.0, < 2.3.3, and >= 2.4.0, < 2.4.2.

Exploitation Mechanism

Attackers can exploit this vulnerability by sending crafted requests to the target system, causing the application to read data from a null buffer and leading to a denial of service.

Mitigation and Prevention

Protecting systems from CVE-2021-29581 involves taking immediate steps and implementing long-term security practices to safeguard against potential threats.

Immediate Steps to Take

It is essential to apply security patches released by TensorFlow to address the vulnerability. Ensure that the patches are promptly deployed on all affected systems.

Long-Term Security Practices

To enhance overall security posture, maintain an updated version of TensorFlow and follow secure coding practices to prevent similar vulnerabilities in the future.

Patching and Updates

The fix for CVE-2021-29581 will be included in TensorFlow 2.5.0. Additionally, patches have been cherrypicked for TensorFlow 2.4.2, TensorFlow 2.3.3, TensorFlow 2.2.3, and TensorFlow 2.1.4 to mitigate the vulnerability.