CVE-2021-40830 : What You Need to Know

This CVE involves the AWS IoT Device SDK versions for Java, Python, C++, Node.js on Unix systems not correctly handling Certificate Authority (CA) overrides, potentially leading to security risks.

Understanding CVE-2021-40830

This section provides insights into the nature of the vulnerability.

What is CVE-2021-40830?

The AWS IoT Device SDK v2 for Java, Python, C++, and Node.js incorrectly appends user-supplied CAs to root CAs instead of overriding them on Unix systems. This flaw could allow attackers to bypass CA pinning by compromising trust stores.

The Impact of CVE-2021-40830

The vulnerability has a CVSS base score of 6.3 (Medium severity) with high impacts on confidentiality, integrity, and availability. Attackers can potentially spoof MQTT brokers, but cannot forward the data without users' private keys.

Technical Details of CVE-2021-40830

Detailed technical information on the vulnerability.

Vulnerability Description

The CA override function behavior in the AWS IoT Device SDKs on Unix systems is inconsistent, enabling potential CA pinning bypass attacks.

Affected Systems and Versions

AWS IoT Device SDK v2 for Java versions < 1.5.0
AWS IoT Device SDK v2 for Python versions < 1.6.1
AWS IoT Device SDK v2 for C++ versions < 1.12.7
AWS IoT Device SDK v2 for Node.js versions < 1.5.3
AWS-C-IO 0.10.4

Exploitation Mechanism

Attackers accessing trust stores or compromising CAs in the system's trust store could exploit this issue to impersonate MQTT brokers.

Mitigation and Prevention

Measures to address and prevent the vulnerability.

Immediate Steps to Take

Update the AWS IoT Device SDK to the latest versions.

Long-Term Security Practices

Review and secure trust stores regularly.
Implement strict key management practices.

Patching and Updates

Regularly apply patches and updates from Amazon Web Services to mitigate security risks.