CVE-2019-6842 : Vulnerability Insights and Analysis

The Modicon M580, Modicon M340, Modicon BMxCRA, and 140CRA modules are vulnerable to a Denial of Service (DoS) attack during a firmware upgrade due to improper handling of exceptional conditions.

Understanding CVE-2019-6842

This CVE involves a vulnerability in Schneider Electric's Modicon PLC modules that can be exploited to launch a DoS attack.

What is CVE-2019-6842?

The vulnerability in Modicon M580, Modicon M340, Modicon BMxCRA, and 140CRA modules allows attackers to disrupt PLC operations by sending a malicious package during a firmware upgrade.

The Impact of CVE-2019-6842

Attackers can exploit this vulnerability to cause a Denial of Service (DoS) on the Programmable Logic Controller (PLC).
The attack is executed by sending a package without the required web server image via the FTP protocol.

Technical Details of CVE-2019-6842

This section provides technical insights into the vulnerability.

Vulnerability Description

The vulnerability, identified as CWE-755, stems from improper handling of exceptional conditions during firmware upgrades on the affected Schneider Electric modules.

Affected Systems and Versions

Products: Modicon M580, Modicon M340, Modicon BMxCRA / 140CRA modules
All firmware versions of the mentioned modules are susceptible to this vulnerability.

Exploitation Mechanism

Attackers exploit the vulnerability by sending a package lacking the necessary web server image via the FTP protocol.

Mitigation and Prevention

Protecting systems from CVE-2019-6842 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply security patches provided by Schneider Electric promptly.
Implement network segmentation to isolate PLCs from potentially malicious traffic.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Regularly update firmware and software to mitigate known vulnerabilities.
Conduct security assessments and penetration testing to identify and address weaknesses.

Patching and Updates

Stay informed about security advisories and updates from Schneider Electric.
Ensure all systems are running the latest firmware versions to mitigate the risk of exploitation.