CVE-2018-5440

Name: CVE-2018-5440
Creator: NVD / NIST
Published: 2018-02-15T10:29:00.68+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.12%

Last modified Jun 17, 2026

CVE-2018-5440 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. A Stack-based Buffer Overflow issue was discovered in 3S-Smart CODESYS Web Server. Specifically: all Microsoft Windows (also WinCE) based CODESYS web servers running stand-alone Version 2.3, or as part of the CODESYS runtime system running prior to Version V1.1.9.19. EPSS estimates a 3.12% chance of exploitation in the next 30 days.

Description

A Stack-based Buffer Overflow issue was discovered in 3S-Smart CODESYS Web Server. Specifically: all Microsoft Windows (also WinCE) based CODESYS web servers running stand-alone Version 2.3, or as part of the CODESYS runtime system running prior to Version V1.1.9.19. A crafted request may cause a buffer overflow and could therefore execute arbitrary code on the web server or lead to a denial-of-service condition due to a crash in the web server.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

3.12%

86.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
3s-Software	Codesys Runtime System	< 1.1.9.19
3s-Software	Codesys Web Server	2.3

References

http://www.securityfocus.com/bid/102909Third Party Advisory, VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-18-032-02Third Party Advisory, US Government Resource
http://www.securityfocus.com/bid/102909Third Party Advisory, VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-18-032-02Third Party Advisory, US Government Resource

Timeline

Published: Feb 15, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-5440?

How severe is CVE-2018-5440?

CVE-2018-5440 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.12% probability of exploitation in the next 30 days.

How do I fix CVE-2018-5440?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-5440?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST