# CVE-2018-5440: Memory corruption in 3S-Smart Software Solutions GmbH CODESYS Web Server

> A stack-based buffer overflow in the CODESYS Web Server allows attackers to execute arbitrary code or cause a denial of service via crafted requests.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Feb 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-8jg4-q5rf-9hjg

## What is CVE-2018-5440?

CVE-2018-5440 is a critical memory corruption vulnerability in 3S-Smart Software Solutions GmbH CODESYS Web Server, published on 15 Feb 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-787 (Out-of-bounds Write), CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2018-5440?

It affects 2 products.


Products: 3s-Software Codesys Runtime System, 3s-Software Codesys Web Server.

## How do I fix CVE-2018-5440?

No fix has been published for CVE-2018-5440 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-5440 being exploited?

There is no known exploitation of CVE-2018-5440 in the wild and no public exploit code.

## Other vulnerabilities in 3S-Smart Software Solutions GmbH CODESYS Web Server

- [CVE-2012-6069](https://insights.sbomify.com/CVE-2012-6069/): 3S CoDeSys Relative Path Traversal (critical 10.0)
- [CVE-2012-6068](https://insights.sbomify.com/CVE-2012-6068/): 3S CoDeSys Improper Access Control (critical 9.8)
- [CVE-2014-0760](https://insights.sbomify.com/CVE-2014-0760/): Festo CECX-X-(C1/M1) Controller Improper Authentication (critical 9.3)
- [CVE-2014-0769](https://insights.sbomify.com/CVE-2014-0769/): Festo CECX-X-(C1/M1) Controller Improper Authentication (critical 9.3)
- [CVE-2015-6482](https://insights.sbomify.com/CVE-2015-6482/): Null dereference in n/a (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-5440 and fix it if it is affected.

What it is: CVE-2018-5440 is a critical memory corruption vulnerability in 3S-Smart Software Solutions GmbH CODESYS Web Server, published on 15 Feb 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-5440 in the wild and no public exploit code.

Affected product: 3S-Smart Software Solutions GmbH CODESYS Web Server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2018-5440/ (Markdown: https://insights.sbomify.com/CVE-2018-5440/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-5440
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-5440
- OSV: https://osv.dev/vulnerability/CVE-2018-5440

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From sbomify Insights: https://insights.sbomify.com/CVE-2018-5440/
Summaries are generated and may contain mistakes; the official description above is the record.