A Stack-based Buffer Overflow issue was discovered in 3S-Smart CODESYS Web Server.

published 2018-02-15 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-17210

cvss: 9.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 3.1%; EPSS 3.1% chance of exploitation in 30 days, percentile 87%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

3s-software codesys_runtime_system 1.1.9.19

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-18-032-02 updated 2018-02-01 cvss 9.8

3S-Smart Software Solutions GmbH CODESYS Web Server

3S-Smart Software Solutions GmbH CODESYS Web Server 2.3, < 1.1.9.19
affected: mitigation “Currently, 3S-Smart Software Solutions GmbH has not identified any workarounds for this vulnerability.” codesys.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

3.10% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

n/a 3S-Smart Software Solutions GmbH CODESYS Web Server

Classification

Weakness

CWE-121 Stack-based Buffer Overflow
CWE-787 Out-of-bounds Write

References

securityfocus.com /bid/102909
vdb-entry, third-party-advisory
ics-cert.us-cert.gov /advisories/ICSA-18-032-02
third-party-advisory, us-government-resource

Sources

CVE List CVE-2018-5440
NVD CVE-2018-5440

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary