# CVE-2023-20089: Denial of service in Cisco NX-OS System Software in ACI Mode

> An adjacent attacker can cause a memory leak and device reload by sending crafted LLDP packets to Cisco Nexus switches in ACI mode.

- **Severity:** High 7.4 (`CVSS:3.1/AV:A/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Feb 2023
- **Updated:** 25 Oct 2024
- **Also known as:** GHSA-qg8x-2gcc-v7rf

## What is CVE-2023-20089?

CVE-2023-20089 is a high-severity denial of service vulnerability in Cisco Nx-Os, published on 23 Feb 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in the Link Layer Discovery Protocol (LLDP) feature for Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) Mode could allow an unauthenticated, adjacent attacker to cause a memory leak, which could result in an unexpected reload of the device. This vulnerability is due to incorrect error checking when parsing ingress LLDP packets. An attacker could exploit this vulnerability by sending a steady stream of crafted LLDP packets to an affected device. A successful exploit could allow the attacker to cause a memory leak, which could result in a denial of service (DoS) condition when the device unexpectedly reloads. Note: This vulnerability cannot be exploited by transit traffic through the device. The crafted LLDP packet must be targeted to a directly connected interface, and the attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent). In addition, the attack surface for this vulnerability can be reduced by disabling LLDP on interfaces where it is not required.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime), CWE-789 (Memory Allocation with Excessive Size Value)

## Which versions are affected by CVE-2023-20089?

It affects 1 product.


Products: Cisco Nx-Os.

## How do I fix CVE-2023-20089?

No fix has been published for CVE-2023-20089 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-20089 being exploited?

There is no known exploitation of CVE-2023-20089 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Nx-Os

- [CVE-2024-20399](https://insights.sbomify.com/CVE-2024-20399/): Cisco NX-OS Command Injection (medium 6.0, exploited in the wild)
- [CVE-2021-1361](https://insights.sbomify.com/CVE-2021-1361/): Cisco NX-OS Software Unauthenticated Arbitrary File Actions Vulnerability (critical 9.8)
- [CVE-2018-0301](https://insights.sbomify.com/CVE-2018-0301/): Memory corruption in Cisco NX-OS unknown (critical 9.8)
- [CVE-2016-1453](https://insights.sbomify.com/CVE-2016-1453/): Memory corruption in n/a (critical 9.8)
- [CVE-2016-1341](https://insights.sbomify.com/CVE-2016-1341/): Hardcoded credentials in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-20089 and fix it if it is affected.

What it is: CVE-2023-20089 is a high-severity denial of service vulnerability in Cisco Nx-Os, published on 23 Feb 2023. 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-2023-20089 in the wild and no public exploit code.

Affected product: Cisco Nx-Os. 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-2023-20089/ (Markdown: https://insights.sbomify.com/CVE-2023-20089/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-20089
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-20089
- OSV: https://osv.dev/vulnerability/CVE-2023-20089

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-20089/
Summaries are generated and may contain mistakes; the official description above is the record.