# CVE-2023-20200: Denial of service in Cisco Firepower Extensible Operating System (FXOS)

> An authenticated remote attacker can cause a denial of service on Cisco Firepower and UCS devices by sending crafted SNMP requests, requiring valid credentials or community strings.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Aug 2023
- **Updated:** 1 Jul 2025
- **Also known as:** GHSA-vrx2-vjh6-fhxx

## What is CVE-2023-20200?

CVE-2023-20200 is a high-severity denial of service vulnerability in Cisco Firepower Extensible Operating System (FXOS), published on 23 Aug 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability in the Simple Network Management Protocol (SNMP) service of Cisco FXOS Software for Firepower 4100 Series and Firepower 9300 Security Appliances and of Cisco UCS 6300 Series Fabric Interconnects could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

 This vulnerability is due to the improper handling of specific SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

 Note: This vulnerability affects all supported SNMP versions. To exploit this vulnerability through SNMPv2c or earlier, an attacker must know the SNMP community string that is configured on an affected device. To exploit this vulnerability through SNMPv3, the attacker must have valid credentials for an SNMP user who is configured on the affected device.

Weakness: CWE-732 (Incorrect Permission Assignment for Critical Resource), CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2023-20200?

It affects 8 products.


Products: Cisco Firepower 4112 Firmware, Cisco Firepower 4115, Cisco Firepower 4125 Firmware, Cisco Firepower 4143 Firmware, Cisco Firepower 9300 Firmware, Cisco Ucs 6324 Fabric Interconnect Firmware, Cisco Ucs 6332-16up Fabric Interconnect Firmware, Cisco Ucs 6332 Fabric Interconnect Firmware.

## How do I fix CVE-2023-20200?

No fix has been published for CVE-2023-20200 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-20200 being exploited?

There is no known exploitation of CVE-2023-20200 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-20200 and fix it if it is affected.

What it is: CVE-2023-20200 is a high-severity denial of service vulnerability in Cisco Firepower Extensible Operating System (FXOS), published on 23 Aug 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-20200 in the wild and no public exploit code.

Affected product: Cisco Firepower Extensible Operating System (FXOS). 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-2023-20200/ (Markdown: https://insights.sbomify.com/CVE-2023-20200/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-20200
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-20200
- OSV: https://osv.dev/vulnerability/CVE-2023-20200

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From sbomify Insights: https://insights.sbomify.com/CVE-2023-20200/
Summaries are generated and may contain mistakes; the official description above is the record.