# CVE-2020-3172: Cisco FXOS and NX-OS Software Cisco Discovery Protocol Arbitrary Code Execution and Denial of Service Vulnerability

> An adjacent attacker can execute arbitrary code as root or cause denial of service via crafted CDP packets due to insufficient validation.

- **Severity:** High 8.8 (`CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 26 Feb 2020
- **Updated:** 15 Nov 2024
- **Also known as:** GHSA-cvm3-233f-g2vf

## What is CVE-2020-3172?

CVE-2020-3172 is a high-severity memory corruption vulnerability in Cisco Firepower Extensible Operating System, published on 26 Feb 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in the Cisco Discovery Protocol feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code as root or cause a denial of service (DoS) condition on an affected device. The vulnerability exists because of insufficiently validated Cisco Discovery Protocol packet headers. An attacker could exploit this vulnerability by sending a crafted Cisco Discovery Protocol packet to a Layer 2-adjacent affected device. A successful exploit could allow the attacker to cause a buffer overflow that could allow the attacker to execute arbitrary code as root or cause a DoS condition on the affected device. Note: Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent). Note: This vulnerability is different from the following Cisco FXOS and NX-OS Software Cisco Discovery Protocol vulnerabilities that Cisco announced on Feb. 5, 2020: Cisco FXOS, IOS XR, and NX-OS Software Cisco Discovery Protocol Denial of Service Vulnerability and Cisco NX-OS Software Cisco Discovery Protocol Remote Code Execution Vulnerability.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2020-3172?

It affects 3 products.


Products: Cisco Firepower Extensible Operating System, Cisco Nx-Os, Cisco Ucs Manager.

## How do I fix CVE-2020-3172?

No fix has been published for CVE-2020-3172 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3172 being exploited?

There is no known exploitation of CVE-2020-3172 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Firepower Extensible Operating System

- [CVE-2018-0310](https://insights.sbomify.com/CVE-2018-0310/): Information disclosure in Cisco FXOS and NX-OS unknown (critical 9.8)
- [CVE-2015-6435](https://insights.sbomify.com/CVE-2015-6435/): Command injection in n/a (critical 9.8)
- [CVE-2021-1368](https://insights.sbomify.com/CVE-2021-1368/): Memory corruption in Cisco NX-OS Software (high 8.8)
- [CVE-2020-3456](https://insights.sbomify.com/CVE-2020-3456/): Cisco FXOS Software Firepower Chassis Manager Cross-Site Request Forgery Vulnerability (high 8.8)
- [CVE-2018-0395](https://insights.sbomify.com/CVE-2018-0395/): Cisco FXOS and NX-OS Software Link Layer Discovery Protocol Denial of Service Vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3172 and fix it if it is affected.

What it is: CVE-2020-3172 is a high-severity memory corruption vulnerability in Cisco Firepower Extensible Operating System, published on 26 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-2020-3172 in the wild and no public exploit code.

Affected product: Cisco Firepower Extensible Operating System. 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-2020-3172/ (Markdown: https://insights.sbomify.com/CVE-2020-3172/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3172
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3172
- OSV: https://osv.dev/vulnerability/CVE-2020-3172

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3172/
Summaries are generated and may contain mistakes; the official description above is the record.