PT-2018-1524 · Schneider Electric · Modicon M221

CVE-2018-7791 · Published 2018-07-30 · Updated 2026-05-29

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 Modicon M221 versions prior to V1.6.2.0

Description A Permissions, Privileges, and Access Control issue exists, allowing unauthorized users to overwrite the original password with their own. This could enable an attacker to upload the original program from the PLC if the vulnerability is exploited. The issue is caused by weaknesses in the authentication procedure, which can be exploited remotely to rewrite passwords.

Recommendations For versions prior to V1.6.2.0, update the firmware to V1.6.2.0 or later to resolve the issue. As a temporary workaround, consider restricting access to the PLC to minimize the risk of exploitation. Avoid using the device remotely until the issue is resolved by updating the firmware.

Fix

Improper Authentication

Improper Access Control

Weakness Enumeration

CWE-264

CWE-287

CWE-284

Related Identifiers

BDU:2018-01079

CVE-2018-7791

Affected Products

Modicon M221

References · 7

• https://nvd.nist.gov/vuln/detail/CVE-2018-7791 · Security Note
• https://osv.dev/vulnerability/CVE-2018-7791 · Vendor Advisory
• https://bdu.fstec.ru/vul/2018-01079 · Security Note
• https://schneider-electric.com/en/download/document/SEVD-2018-235-01 · Vendor Advisory
• http://securityfocus.com/bid/105182 · Note
• https://t.me/cveNotify/165208 · Telegram Post
• https://securityfocus.com/bid/105182/info · Note