CVE-2019-6821

Name: CVE-2019-6821
Creator: NVD / NIST
Published: 2019-05-22T20:29:02.183+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.93%

Last modified Jun 17, 2026

CVE-2019-6821 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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.. EPSS estimates a 1.93% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS Probability

1.93%

77.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Schneider-Electric	Modicon M580 Firmware	< 2.30
Schneider-Electric	Modicon M340 Firmware	All versions
Schneider-Electric	Modicon Quantum Firmware	All versions
Schneider-Electric	Modicon Premium Firmware	All versions

References

http://www.securityfocus.com/bid/108366Third Party Advisory, VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-19-136-01Third Party Advisory, US Government Resource
https://www.schneider-electric.com/en/download/document/SEVD-2019-134-03/Patch, Vendor Advisory
http://www.securityfocus.com/bid/108366Third Party Advisory, VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-19-136-01Third Party Advisory, US Government Resource
https://www.schneider-electric.com/en/download/document/SEVD-2019-134-03/Patch, Vendor Advisory

Timeline

Published: May 22, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-6821?

How severe is CVE-2019-6821?

CVE-2019-6821 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.93% probability of exploitation in the next 30 days.

How do I fix CVE-2019-6821?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-6821?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST