# CVE-2019-1804: Cisco Nexus 9000 Series Fabric Switches Application Centric Infrastructure Mode Default SSH Key Vulnerability

> An unauthenticated remote attacker can gain root access to Cisco Nexus 9000 switches via IPv6 using a default SSH key.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 May 2019
- **Updated:** 19 Nov 2024
- **Also known as:** GHSA-9hxx-97w4-fh95

## What is CVE-2019-1804?

CVE-2019-1804 is a critical vulnerability in Cisco NX-OS Software for Nexus 9000 Series Fabric Switches ACI Mode 11.0.1b, published on 3 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the SSH key management for the Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch Software could allow an unauthenticated, remote attacker to connect to the affected system with the privileges of the root user. The vulnerability is due to the presence of a default SSH key pair that is present in all devices. An attacker could exploit this vulnerability by opening an SSH connection via IPv6 to a targeted device using the extracted key materials. An exploit could allow the attacker to access the system with the privileges of the root user. This vulnerability is only exploitable over IPv6; IPv4 is not vulnerable.

Weakness: CWE-1188 (Initialization of a Resource with an Insecure Default), CWE-310

## Which versions are affected by CVE-2019-1804?

It affects 13 products.


Products: Cisco Nexus 93108tc-Ex Firmware, Cisco Nexus 93120tx Firmware, Cisco Nexus 93128tx Firmware, Cisco Nexus 93180yc-Ex Firmware, Cisco Nexus 9332pq Firmware, Cisco Nexus 9372px Firmware, Cisco Nexus 9372tx Firmware, Cisco Nexus 9396px Firmware, Cisco Nexus 9396tx Firmware, Cisco Nexus 9500 Firmware, Cisco Nexus 9504 Firmware, Cisco Nexus 9508 Firmware, Cisco Nexus 9516 Firmware.

## How do I fix CVE-2019-1804?

No fix has been published for CVE-2019-1804 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1804 being exploited?

There is no known exploitation of CVE-2019-1804 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-1804 and fix it if it is affected.

What it is: CVE-2019-1804 is a critical vulnerability in Cisco NX-OS Software for Nexus 9000 Series Fabric Switches ACI Mode 11.0.1b, published on 3 May 2019. 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-2019-1804 in the wild and no public exploit code.

Affected product: Cisco NX-OS Software for Nexus 9000 Series Fabric Switches ACI Mode 11.0.1b. 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-2019-1804/ (Markdown: https://insights.sbomify.com/CVE-2019-1804/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1804
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1804
- OSV: https://osv.dev/vulnerability/CVE-2019-1804

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-1804/
Summaries are generated and may contain mistakes; the official description above is the record.