# CVE-2015-2923: Misconfiguration in n/a

> Remote attackers can reconfigure hop-limit settings in FreeBSD IPv6 via malicious Router Advertisement messages, potentially bypassing network security controls.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Feb 2020
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-vgpp-7j95-7pmj

## What is CVE-2015-2923?

CVE-2015-2923 is a medium-severity vulnerability in Freebsd Freebsd, published on 20 Feb 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The Neighbor Discovery (ND) protocol implementation in the IPv6 stack in FreeBSD through 10.1 allows remote attackers to reconfigure a hop-limit setting via a small hop_limit value in a Router Advertisement (RA) message.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2015-2923?

It affects 1 product.


Products: Freebsd Freebsd.

## How do I fix CVE-2015-2923?

Apply the vendor's patch.

## Is CVE-2015-2923 being exploited?

There is no known exploitation of CVE-2015-2923 in the wild and no public exploit code.

## Other vulnerabilities in Freebsd Freebsd

- [CVE-2018-17160](https://insights.sbomify.com/CVE-2018-17160/): Memory corruption in FreeBSD (critical 10.0)
- [CVE-2014-3954](https://insights.sbomify.com/CVE-2014-3954/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-4304](https://insights.sbomify.com/CVE-2006-4304/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-0226](https://insights.sbomify.com/CVE-2006-0226/): Integer overflow in n/a (critical 10.0)
- [CVE-2004-0002](https://insights.sbomify.com/CVE-2004-0002/): Denial of service in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2015-2923 and fix it if it is affected.

What it is: CVE-2015-2923 is a medium-severity vulnerability in Freebsd Freebsd, published on 20 Feb 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2015-2923 in the wild and no public exploit code.

Affected product: Freebsd Freebsd. 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-2015-2923/ (Markdown: https://insights.sbomify.com/CVE-2015-2923/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-2923
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-2923
- OSV: https://osv.dev/vulnerability/CVE-2015-2923

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-2923/
Summaries are generated and may contain mistakes; the official description above is the record.