# CVE-2023-3663: CODESYS: Missing integrity check in CODESYS Development System

> An unauthenticated remote attacker can manipulate HTTP notification content in CODESYS Development System due to missing integrity checks.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** No
- **Published:** 3 Aug 2023
- **Updated:** 27 Feb 2025
- **Also known as:** GHSA-c86m-wfx2-qmx9

## What is CVE-2023-3663?

CVE-2023-3663 is a high-severity missing authorization vulnerability in CODESYS Development System, published on 3 Aug 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

In CODESYS Development System versions from 3.5.11.20 and before 3.5.19.20 a missing integrity check might allow an unauthenticated remote attacker to manipulate the content of notifications received via HTTP by the CODESYS notification server.

Weakness: CWE-940 (Improper Verification of Source of a Communication Channel)

## Which versions are affected by CVE-2023-3663?

It affects 1 product.


Products: Codesys Development System.

## How do I fix CVE-2023-3663?

No fix has been published for CVE-2023-3663 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-3663 being exploited?

There is no known exploitation of CVE-2023-3663 in the wild and no public exploit code.

## Other vulnerabilities in CODESYS Development System

- [CVE-2021-21863](https://insights.sbomify.com/CVE-2021-21863/): Deserialization in CODESYS (high 8.8)
- [CVE-2021-21865](https://insights.sbomify.com/CVE-2021-21865/): Deserialization in CODESYS (high 8.8)
- [CVE-2021-21866](https://insights.sbomify.com/CVE-2021-21866/): Deserialization in CODESYS (high 8.8)
- [CVE-2026-44468](https://insights.sbomify.com/CVE-2026-44468/): Incorrect Default Permissions in CODESYS Development System (high 8.5)
- [CVE-2026-44469](https://insights.sbomify.com/CVE-2026-44469/): Incorrect Default Permissions in CODESYS Development System (high 8.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-3663 and fix it if it is affected.

What it is: CVE-2023-3663 is a high-severity missing authorization vulnerability in CODESYS Development System, published on 3 Aug 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-3663 in the wild and no public exploit code.

Affected product: CODESYS Development System. 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-2023-3663/ (Markdown: https://insights.sbomify.com/CVE-2023-3663/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-3663
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-3663
- OSV: https://osv.dev/vulnerability/CVE-2023-3663

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-3663/
Summaries are generated and may contain mistakes; the official description above is the record.