# CVE-2023-3338: Crash due to a null pointer dereference in the dn_nsp_send function

> A remote attacker can crash the Linux kernel via a null pointer dereference in the DECnet protocol, causing a denial of service.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Jun 2023
- **Updated:** 14 Oct 2026
- **Also known as:** AZL-27636, AZL-31687, AZL-34801, AZL-61792, DEBIAN-CVE-2023-3338, GHSA-qj9w-7hh5-mf2q, UBUNTU-CVE-2023-3338

## What is CVE-2023-3338?

CVE-2023-3338 is a medium-severity vulnerability in Debian Debian Linux, published on 30 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A null pointer dereference flaw was found in the Linux kernel's DECnet networking protocol. This issue could allow a remote user to crash the system.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-3338?

It affects 3 products.


Products: Debian Debian Linux, Linux kernel, Netapp Active Iq Unified Manager.

## How do I fix CVE-2023-3338?

Apply the vendor's patch.

## Is CVE-2023-3338 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-3338 exists.

Public exploit code:

- Linux kernel LPE practice with an NPD vulnerability (github_poc): https://github.com/TurtleARM/CVE-2023-3338-DECPwn

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-3338 and fix it if it is affected.

What it is: CVE-2023-3338 is a medium-severity vulnerability in Debian Debian Linux, published on 30 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-3338 exists.

Affected product: Debian Debian Linux. 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-2023-3338/ (Markdown: https://insights.sbomify.com/CVE-2023-3338/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-3338
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-3338
- OSV: https://osv.dev/vulnerability/CVE-2023-3338

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-3338/
Summaries are generated and may contain mistakes; the official description above is the record.