PT-2018-14: Buffer Overflow in PHOENIX CONTACT FL SWITCH

Vulnerable products

PHOENIX CONTACT FL SWITCH 3xxx, 4xxx, and 48xxx
Firmware version: 1.33 and earlier


Severity level

Severity level: High
Impact: Arbitrary Code Execution
Access Vector: Remote

CVSS v3:
Base Score: 9.0
Vector: (AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H)

CVE: CVE-2018-10731

Vulnerability description

The specialists of the Positive Research center have detected a Buffer Overflow vulnerability in PHOENIX CONTACT FL SWITCH.

A buffer overflow vulnerability in Phoenix Contact managed FL SWITCH due to improper handling of very large cookies allows attackers to obtain unauthorized access to the device’s operating system and inject executable code.

How to fix

Update firmware to the latest version

Advisory status

22.02.2018 - Vendor gets vulnerability details
16.05.2018 - Vendor releases fixed version and details
29.08.2018 - Public disclosure


The vulnerability was detected by Vyacheslav Moskvin, Semen Sokolov, 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+