CVE-2021-34431 Explained : Impact and Mitigation

Eclipse Mosquitto versions 1.6 to 2.0.10 are impacted by a vulnerability that could lead to a denial-of-service (DoS) attack. An authenticated client using MQTT v5 could trigger a memory leak by sending a specifically crafted CONNECT message to the broker.

Understanding CVE-2021-34431

This section provides insights into the impact, technical details, and mitigation strategies related to CVE-2021-34431.

What is CVE-2021-34431?

CVE-2021-34431 is a security flaw present in Eclipse Mosquitto versions 1.6 to 2.0.10, allowing an attacker to exploit a memory leak through a malicious CONNECT message sent by an authenticated client using MQTT v5.

The Impact of CVE-2021-34431

The vulnerability can result in a memory leak, potentially enabling a DoS attack against the broker, causing disruption and unavailability of MQTT services.

Technical Details of CVE-2021-34431

Let's delve into the specific technical aspects of the vulnerability.

Vulnerability Description

When an authenticated client connects with MQTT v5 and sends a crafted CONNECT message to the broker in Eclipse Mosquitto versions 1.6 to 2.0.10, it triggers a memory leak that could be exploited for a DoS attack.

Affected Systems and Versions

The affected systems include Eclipse Mosquitto versions 1.6 to 2.0.10. Users operating these versions are at risk of potential exploitation of this memory leak vulnerability.

Exploitation Mechanism

By exploiting the crafted CONNECT message, an attacker could initiate a DoS attack, causing the broker to become unresponsive and unavailable.

Mitigation and Prevention

Understanding how to mitigate the risks posed by CVE-2021-34431 is crucial for maintaining the security of MQTT services.

Immediate Steps to Take

For immediate mitigation, users are advised to update their Eclipse Mosquitto installations to a patched version that addresses the memory leak vulnerability.

Long-Term Security Practices

Implementing strong authentication mechanisms, monitoring for anomalous behavior, and applying regular security updates are essential for enhancing the long-term security posture.

Patching and Updates

It is recommended to stay informed about security advisories from Eclipse Mosquitto and promptly apply patches and updates to address known vulnerabilities.