PT-2018-18: Buffer Overflow in Schneider Electric's Modicon Premium, Modicon Quantum, and Modicon M340

Vulnerable products

Modicon Premium, Modicon Quantum, and Modicon M340
Version: all versions


Severity level

Severity level: High
Impact: Denial of Service
Access Vector: Remote

CVSS v3:
Base Score: 7.5
Vector: (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVE: CVE-2018-7759

Vulnerability description

The specialists of the Positive Research center have detected a Buffer Overflow vulnerability in Schneider Electric's Modicon Premium, Modicon Quantum, and Modicon M340.

A buffer overflow vulnerability, due to the length of the source string specified as the number of bytes to be copied (instead of the buffer size), allows attackers to cause a denial of service.

How to fix

Use the vendor's advisory:

Advisory status

28.04.2017 - Vendor gets vulnerability details
22.03.2018 - Vendor releases fixed version and details
03.09.2018 - Public disclosure


The vulnerability was detected by Nikita Maximov, Positive Research Center (Positive Technologies Company)


Reports on the vulnerabilities previously discovered by Positive Research:

About Positive Technologies

Positive Technologies is a leading provider of vulnerability assessment, compliance management and threat analysis solutions to more than 1,000 global enterprise clients. Our solutions work seamlessly across your entire business: securing applications in development; assessing your network and application vulnerabilities; assuring compliance with regulatory requirements; and blocking real-time attacks. Our commitment to clients and research has earned Positive Technologies a reputation as one of the foremost authorities on SCADA, Banking, Telecom, Web Application and ERP security, and distinction as the #1 fastest growing Security and Vulnerability Management firm in 2012, as shown in an IDC report*. To learn more about Positive Technologies please visit

*Source: IDC Worldwide Security and Vulnerability Management 2013-2017 Forecast and 2012 Vendor Shares, doc #242465, August 2013. Based on year-over-year revenue growth in 2012 for vendors with revenues of $20M+