# CVE-2019-18858: Memory corruption in n/a

> A buffer overflow in the CODESYS web server allows attackers to execute arbitrary code or cause a denial of service.

- **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:** 20 Nov 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-v33j-h2wh-c582

## What is CVE-2019-18858?

CVE-2019-18858 is a critical memory corruption vulnerability in Codesys Control Runtime System Toolkit, published on 20 Nov 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

CODESYS 3 web server before 3.5.15.20, as distributed with CODESYS Control runtime systems, has a Buffer Overflow.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2019-18858?

It affects 14 products.


Products: Codesys Control for Beaglebone, Codesys Control for Empc-A\/Imx6, Codesys Control for Iot2000, Codesys Control for Linux, Codesys Control for Pfc100, Codesys Control for Pfc200, Codesys Control for Plcnext, Codesys Control for Raspberry Pi, Codesys Control Rte, Codesys Control Runtime System Toolkit, Codesys Control Win, Codesys Embedded Target Visu Toolkit, Codesys Hmi, Codesys Remote Target Visu Toolkit.

## How do I fix CVE-2019-18858?

No fix has been published for CVE-2019-18858 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-18858 being exploited?

There is no known exploitation of CVE-2019-18858 in the wild and no public exploit code.

## Other vulnerabilities in Codesys Control Runtime System Toolkit

- [CVE-2020-10245](https://insights.sbomify.com/CVE-2020-10245/): Memory corruption in n/a (critical 9.8)
- [CVE-2019-13548](https://insights.sbomify.com/CVE-2019-13548/): Memory corruption in CODESYS V3 web server (critical 9.8)
- [CVE-2018-25048](https://insights.sbomify.com/CVE-2018-25048/): Codesys Runtime Improper Limitation of a Pathname (high 8.8)
- [CVE-2019-9008](https://insights.sbomify.com/CVE-2019-9008/): Privilege escalation in n/a (high 8.8)
- [CVE-2020-12069](https://insights.sbomify.com/CVE-2020-12069/): CODESYS V3 prone to Inadequate Password Hashing (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-18858 and fix it if it is affected.

What it is: CVE-2019-18858 is a critical memory corruption vulnerability in Codesys Control Runtime System Toolkit, published on 20 Nov 2019. 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-2019-18858 in the wild and no public exploit code.

Affected product: Codesys Control Runtime System Toolkit. 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-2019-18858/ (Markdown: https://insights.sbomify.com/CVE-2019-18858/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-18858
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-18858
- OSV: https://osv.dev/vulnerability/CVE-2019-18858

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-18858/
Summaries are generated and may contain mistakes; the official description above is the record.