CVE-2021-40829 : Exploit Details and Defense Strategies

This CVE article provides details about TLS hostname validation issues within AWS IoT Device SDKs on macOS.

Understanding CVE-2021-40829

This section delves into the implications and technical aspects of the CVE.

What is CVE-2021-40829?

Connections initialized by various AWS IoT Device SDKs on macOS failed to verify server certificate hostname during TLS handshake, posing a security risk.

The Impact of CVE-2021-40829

The vulnerability holds an overall base score of 6.3, making it a medium-severity issue. High impacts on confidentiality, integrity, and availability are observed.

Technical Details of CVE-2021-40829

Exploring the vulnerability in depth.

Vulnerability Description

The affected AWS IoT Device SDK versions for macOS did not validate server certificate hostname during TLS handshake when overriding Certificate Authorities (CA) in trust stores.

Affected Systems and Versions

AWS IoT Device SDK v2 for Java: < 1.4.2
AWS IoT Device SDK v2 for Python: < 1.6.1
AWS IoT Device SDK v2 for C++: < 1.12.7
AWS IoT Device SDK v2 for Node.js: < 1.5.3
AWS-C-IO: < 0.10.5

Exploitation Mechanism

The issue arises due to improper validation of server certificate hostname, allowing man-in-the-middle attacks on connections.

Mitigation and Prevention

Preventative measures and solutions for addressing the CVE.

Immediate Steps to Take

Update affected AWS IoT Device SDK versions to the latest releases.

Long-Term Security Practices

Regularly monitor for security updates and patches.
Implement secure coding practices and adhere to TLS security guidelines.

Patching and Updates

Regularly apply updates for AWS IoT Device SDKs to ensure security and address any known vulnerabilities.