# CVE-2023-2156: Denial of service in Linux kernel (RPL protocol)

> An unauthenticated remote attacker can cause a denial of service in the Linux kernel via improper handling of RPL protocol data.

- **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:** Yes
- **Published:** 9 May 2023
- **Updated:** 2 Aug 2024
- **Also known as:** DEBIAN-CVE-2023-2156, GHSA-7jf7-rx7v-xwqq, SUSE-SU-2023:3658-1, UBUNTU-CVE-2023-2156

## What is CVE-2023-2156?

CVE-2023-2156 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 9 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in the networking subsystem of the Linux kernel within the handling of the RPL protocol. This issue results from the lack of proper handling of user-supplied data, which can lead to an assertion failure. This may allow an unauthenticated remote attacker to create a denial of service condition on the system.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2023-2156?

It affects 4 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `kernel-livepatch-SLE15-SP4_Update_15` | SUSE:Linux Enterprise Live Patching 15 SP4 | All versions | 2-150400.2.1 |
| `kernel-livepatch-SLE15-SP5_Update_2` | SUSE:Linux Enterprise Live Patching 15 SP5 | All versions | 2-150500.2.1 |

Products: Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Redhat Enterprise Linux.

## How do I fix CVE-2023-2156?

Apply the vendor's patch.

## Is CVE-2023-2156 being exploited?

There is no known exploitation of CVE-2023-2156 in the wild and no public exploit code.

## 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-2023-2156 and fix it if it is affected.

What it is: CVE-2023-2156 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 9 May 2023. 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-2023-2156 in the wild and no public exploit code.

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-2023-2156/ (Markdown: https://insights.sbomify.com/CVE-2023-2156/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-2156
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-2156
- OSV: https://osv.dev/vulnerability/CVE-2023-2156

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-2156/
Summaries are generated and may contain mistakes; the official description above is the record.