CVE-2021-41036 Explained : Impact and Mitigation

In versions prior to 1.1 of the Eclipse Paho MQTT C Client, a vulnerability exists where the client does not check rem_len size in readpacket, potentially leading to an out-of-bounds write issue.

Understanding CVE-2021-41036

In this CVE, the Eclipse Paho MQTT C Client is affected by a CWE-787 vulnerability, presenting a risk of out-of-bounds write.

What is CVE-2021-41036?

The Eclipse Paho MQTT C Client, before version 1.1, fails to validate the rem_len parameter in readpacket, opening possibilities for an attacker to execute an out-of-bounds write.

The Impact of CVE-2021-41036

This vulnerability could allow a remote attacker to trigger a buffer overflow, potentially leading to arbitrary code execution or denial of service.

Technical Details of CVE-2021-41036

This section covers the technical aspects of the CVE.

Vulnerability Description

The issue arises from the lack of validation of the rem_len size in readpacket of the Eclipse Paho MQTT C Client, resulting in a security vulnerability.

Affected Systems and Versions

Product: Eclipse Paho MQTT C Client
Vendor: The Eclipse Foundation
Versions Affected: < 1.1.0 (unspecified version type)

Exploitation Mechanism

Exploiting this vulnerability involves sending specially crafted MQTT packets to the affected client, triggering the out-of-bounds write.

Mitigation and Prevention

To address CVE-2021-41036 and enhance security, follow the steps below.

Immediate Steps to Take

Upgrade the Eclipse Paho MQTT C Client to version 1.1.0 or newer.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Conduct regular security audits and code reviews.
Keep software and libraries updated to prevent known vulnerabilities.

Patching and Updates

Stay informed about security patches and updates released by The Eclipse Foundation to address this vulnerability.