CVE-2019-6821 Weak cryptography in Modicon Controllers, Modicon M580 firmware versions prior to V2.30, and all firmware versions of Modicon M340, Modicon Premium, Modicon Quantum

Medium 6.5 Published 22 May 2019 Updated 4 Aug 2024

Insufficiently random values in Modicon PLC firmware allow attackers to hijack TCP connections via Ethernet communication.

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

What is CVE-2019-6821?

CVE-2019-6821 is a medium-severity vulnerability in Modicon Controllers, Modicon M580 firmware versions prior to V2.30, and all firmware versions of Modicon M340, Modicon Premium, Modicon Quantum, published on 22 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

CWE-330: Use of Insufficiently Random Values vulnerability, which could cause the hijacking of the TCP connection when using Ethernet communication in Modicon M580 firmware versions prior to V2.30, and all firmware versions of Modicon M340, Modicon Premium, Modicon Quantum.

Weakness: CWE-330

Which versions are affected by CVE-2019-6821?

It affects 4 products.

Products include Schneider-Electric Modicon M340 Firmware, Schneider-Electric Modicon M580 Firmware, Schneider-Electric Modicon Premium Firmware, Schneider-Electric Modicon Quantum Firmware.

How do I fix CVE-2019-6821?

No fix has been published for CVE-2019-6821 yet. Limit exposure of the affected software until one is available.

Is CVE-2019-6821 being exploited?

There is no known exploitation of CVE-2019-6821 in the wild and no public exploit code.

Sources

Also known as GHSA-pr9h-xjrf-gjcr.