PT-2018-1523 · Schneider Electric · Modicon M221

Published 2018-07-30 · Updated 2026-05-29 · CVE-2018-7790

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions Schneider Electric Modicon M221 versions prior to V1.6.2.0

Description The issue is caused by weaknesses in the authentication procedure, allowing a remote attacker to bypass authentication. This can enable unauthorized users to replay authentication sequences. If exploited, an attacker connected to a Modicon M221 can upload the original program from the PLC.

Recommendations For versions prior to V1.6.2.0, update the firmware to version V1.6.2.0 or later to resolve the issue. As a temporary workaround, consider restricting access to the Modicon M221 to minimize the risk of exploitation.

Fix

Improper Restriction of Excessive Authentication Attempts

Weakness Enumeration

CWE-294

CWE-307

Related Identifiers

BDU:2018-01078

CVE-2018-7790

Affected Products

Modicon M221

References · 7

• https://osv.dev/vulnerability/CVE-2018-7790 · Vendor Advisory
• https://bdu.fstec.ru/vul/2018-01078 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2018-7790 · Security Note
• https://schneider-electric.com/en/download/document/SEVD-2018-235-01 · Vendor Advisory
• https://t.me/cveNotify/165207 · Telegram Post
• http://securityfocus.com/bid/105182 · Note
• https://securityfocus.com/bid/105182/info · Note