CVE-2019-6843 Denial of service in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info)

Medium 4.9 Published 29 Oct 2019 Updated 4 Aug 2024

An attacker can cause a Denial of Service on Schneider Electric Modicon PLCs by uploading an empty firmware package via FTP.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2019-6843?

CVE-2019-6843 is a medium-severity denial of service vulnerability in Modicon M580, Modicon M340, and Modicon BMxCRA / 140CRA modules (see notification for version info), published on 29 Oct 2019. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

A CWE-755: Improper Handling of Exceptional Conditions vulnerability exists in Modicon M580 with firmware (version prior to V3.10), Modicon M340 (all firmware versions), and Modicon BMxCRA and 140CRA modules (all firmware versions), which could cause a Denial of Service attack on the PLC when upgrading the controller with an empty firmware package using FTP protocol.

Weakness: CWE-755

Which versions are affected by CVE-2019-6843?

It affects 4 products.

Products include Schneider-Electric Modicon 140cra Firmware, Schneider-Electric Modicon Bmxcra Firmware, Schneider-Electric Modicon M340 Firmware, Schneider-Electric Modicon M580 Firmware.

How do I fix CVE-2019-6843?

No fix has been published for CVE-2019-6843 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2019-6843 being exploited?

There is no known exploitation of CVE-2019-6843 in the wild and no public exploit code.

Sources

Also known as GHSA-4pf4-m389-3pxh.