CVE-2019-6856 Explained : Impact and Mitigation

A vulnerability known as CWE-754 exists in multiple versions of Schneider Electric's Modicon M580, Modicon M340, Modicon Quantum, and Modicon Premium. This vulnerability could potentially lead to a Denial of Service attack when attempting to write specific physical memory blocks using Modbus TCP.

Understanding CVE-2019-6856

This CVE identifies a critical vulnerability in Schneider Electric's industrial control systems.

What is CVE-2019-6856?

The vulnerability, categorized as CWE-754, involves an Improper Check for Unusual or Exceptional Conditions in the affected Schneider Electric products.

The Impact of CVE-2019-6856

The vulnerability could be exploited to launch a Denial of Service attack, impacting the availability and functionality of the affected systems.

Technical Details of CVE-2019-6856

This section provides detailed technical information about the CVE.

Vulnerability Description

The vulnerability in Modicon M580, Modicon M340, Modicon Quantum, and Modicon Premium allows attackers to disrupt the systems by writing specific physical memory blocks using Modbus TCP.

Affected Systems and Versions

Modicon M580
Modicon M340
Modicon Quantum
Modicon Premium (specific versions detailed in the security notification)

Exploitation Mechanism

Attackers can exploit this vulnerability by sending malicious requests to write specific physical memory blocks using Modbus TCP, leading to a Denial of Service condition.

Mitigation and Prevention

Protecting systems from CVE-2019-6856 is crucial to ensure operational continuity and security.

Immediate Steps to Take

Apply security patches provided by Schneider Electric promptly.
Implement network segmentation to isolate critical systems.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Conduct regular security assessments and audits of industrial control systems.
Train employees on cybersecurity best practices and awareness.
Keep systems updated with the latest security patches and firmware releases.

Patching and Updates

Regularly check for security advisories from Schneider Electric and apply patches as soon as they are released.