# CVE-2024-20446: Cisco NX-OS Software DHCPv6 Relay Agent Denial of Service Vulnerability

> Remote attackers can crash the DHCPv6 relay agent and force device reloads via crafted packets, causing denial of service on Cisco NX-OS devices.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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:** 28 Aug 2024
- **Updated:** 28 Aug 2024
- **Also known as:** GHSA-pwqf-cgf8-rx4x

## What is CVE-2024-20446?

CVE-2024-20446 is a high-severity vulnerability in Cisco NX-OS Software, published on 28 Aug 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the DHCPv6 relay agent of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

This vulnerability is due to improper handling of specific fields in a DHCPv6 RELAY-REPLY message. An attacker could exploit this vulnerability by sending a crafted DHCPv6 packet to any IPv6 address that is configured on an affected device. A successful exploit could allow the attacker to cause the dhcp_snoop process to crash and restart multiple times, causing the affected device to reload and resulting in a DoS condition.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-20446?


## How do I fix CVE-2024-20446?

No fix has been published for CVE-2024-20446 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-20446 being exploited?

There is no known exploitation of CVE-2024-20446 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-20446 and fix it if it is affected.

What it is: CVE-2024-20446 is a high-severity vulnerability in Cisco NX-OS Software, published on 28 Aug 2024. 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-2024-20446 in the wild and no public exploit code.

Affected product: Cisco NX-OS Software. 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-2024-20446/ (Markdown: https://insights.sbomify.com/CVE-2024-20446/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-20446
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-20446
- OSV: https://osv.dev/vulnerability/CVE-2024-20446

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-20446/
Summaries are generated and may contain mistakes; the official description above is the record.