CVE-2018-7791

Name: CVE-2018-7791
Creator: NVD / NIST
Published: 2018-08-29T21:29:01.18+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.90%

Last modified Jun 17, 2026

CVE-2018-7791 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. A Permissions, Privileges, and Access Control vulnerability exists in Schneider Electric's Modicon M221 product (all references, all versions prior to firmware V1.6.2.0). The vulnerability allows unauthorized users to overwrite the original password with their password. EPSS estimates a 1.90% chance of exploitation in the next 30 days.

Description

A Permissions, Privileges, and Access Control vulnerability exists in Schneider Electric's Modicon M221 product (all references, all versions prior to firmware V1.6.2.0). The vulnerability allows unauthorized users to overwrite the original password with their password. If an attacker exploits this vulnerability and overwrite the password, the attacker can upload the original program from the PLC.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

1.90%

77.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Schneider-Electric	Modicon M221 Firmware	< 1.6.2.0

References

http://www.securityfocus.com/bid/105182Third Party Advisory, VDB Entry
https://www.schneider-electric.com/en/download/document/SEVD-2018-235-01/Mitigation, Vendor Advisory
http://www.securityfocus.com/bid/105182Third Party Advisory, VDB Entry
https://www.schneider-electric.com/en/download/document/SEVD-2018-235-01/Mitigation, Vendor Advisory

Timeline

Published: Aug 29, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-7791?

How severe is CVE-2018-7791?

CVE-2018-7791 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.90% probability of exploitation in the next 30 days.

How do I fix CVE-2018-7791?

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-2018-7791?

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

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Source: NVD / NIST