# CVE-2025-56234: Denial of service in n/a

> Attackers can disrupt normal connections on Nanda Automation Technology PLCs by sending random TCP RST packets due to improper sequence number validation.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 29 Sep 2025
- **Updated:** 28 Oct 2025
- **Also known as:** GHSA-wx6w-7qw9-7qj5

## What is CVE-2025-56234?

CVE-2025-56234 is a high-severity denial of service vulnerability in n/a, published on 29 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

AT_NA2000 from Nanda Automation Technology vendor has a denial-of-service vulnerability. For the processing of TCP RST packets, PLC AT_NA2000 has a wide acceptable range of sequence numbers. It does not require the sequence number to exactly match the next expected sequence value, just to be within the current receive window, which violates RFC5961. This flaw allows attackers to send multiple random TCP RST packets to hit the acceptable range of sequence numbers, thereby interrupting normal connections and causing a denial-of-service attack.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2025-56234?


## How do I fix CVE-2025-56234?

No fix has been published for CVE-2025-56234 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-56234 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-56234 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-56234 and fix it if it is affected.

What it is: CVE-2025-56234 is a high-severity denial of service vulnerability in n/a, published on 29 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-56234 exists.

Affected product: n/a. 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-2025-56234/ (Markdown: https://insights.sbomify.com/CVE-2025-56234/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-56234
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-56234
- OSV: https://osv.dev/vulnerability/CVE-2025-56234

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-56234/
Summaries are generated and may contain mistakes; the official description above is the record.