CVE-2018-7790

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-08-29 · updated 2026-06-17
Weakness: CWE-294

Description

An Information Management Error 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 replay authentication sequences. If an attacker exploits this vulnerability and connects to a Modicon M221, the attacker can upload the original program from the PLC.

Affected products

Modicon M221, all references, all versions: before 1.6.2.0 — fixed in 1.6.2.0

How to fix

Upgrade to a fixed version: Modicon M221, all references, all versions 1.6.2.0. Check the vendor advisory for mitigations.

References

http://www.securityfocus.com/bid/105182
https://www.schneider-electric.com/en/download/document/SEVD-2018-235-01/
http://www.securityfocus.com/bid/105182
https://www.schneider-electric.com/en/download/document/SEVD-2018-235-01/

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