# CVE-2022-31803: CODESYS Gateway Server V2 prone to Denial of Service Attack

> An unauthenticated attacker can exhaust TCP connections in CODESYS Gateway Server V2, preventing legitimate clients from connecting.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Jun 2022
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-9348-vpwc-ch78

## What is CVE-2022-31803?

CVE-2022-31803 is a medium-severity denial of service vulnerability in CODESYS Gateway Server V2, published on 24 Jun 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In CODESYS Gateway Server V2 an insufficient check for the activity of TCP client connections allows an unauthenticated attacker to consume all available TCP connections and prevent legitimate users or clients from establishing a new connection to the CODESYS Gateway Server V2. Existing connections are not affected and therefore remain intact.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2022-31803?

It affects 1 product.


Products: Codesys Gateway.

## How do I fix CVE-2022-31803?

No fix has been published for CVE-2022-31803 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-31803 being exploited?

There is no known exploitation of CVE-2022-31803 in the wild and no public exploit code.

## Other vulnerabilities in CODESYS Gateway Server V2

- [CVE-2022-31802](https://insights.sbomify.com/CVE-2022-31802/): Partial string comparison in CODESYS gateway server (critical 9.8)
- [CVE-2022-31804](https://insights.sbomify.com/CVE-2022-31804/): CODESYS Gateway server prone to denial of service attack due to excessive memory allocation (high 7.5)
- [CVE-2021-36764](https://insights.sbomify.com/CVE-2021-36764/): Null dereference in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-31803 and fix it if it is affected.

What it is: CVE-2022-31803 is a medium-severity denial of service vulnerability in CODESYS Gateway Server V2, published on 24 Jun 2022. 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-2022-31803 in the wild and no public exploit code.

Affected product: CODESYS Gateway Server V2. 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-2022-31803/ (Markdown: https://insights.sbomify.com/CVE-2022-31803/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-31803
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-31803
- OSV: https://osv.dev/vulnerability/CVE-2022-31803

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From sbomify Insights: https://insights.sbomify.com/CVE-2022-31803/
Summaries are generated and may contain mistakes; the official description above is the record.