# CVE-2019-1590: Auth bypass in Cisco NX-OS Software for Nexus 9000 Series Fabric Switches ACI Mode

> An attacker with a trusted certificate can bypass TLS validation to gain full control of the ACI fabric components.

- **Severity:** High 8.1 (`CVSS:3.0/AV:N/AC:H/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:** 20 Nov 2024
- **Also known as:** GHSA-9fr7-cq74-hp3w

## What is CVE-2019-1590?

CVE-2019-1590 is a high-severity authentication bypass vulnerability in Cisco Nx-Os, 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 Transport Layer Security (TLS) certificate validation functionality of Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch Software could allow an unauthenticated, remote attacker to perform insecure TLS client authentication on an affected device. The vulnerability is due to insufficient TLS client certificate validations for certificates sent between the various components of an ACI fabric. An attacker who has possession of a certificate that is trusted by the Cisco Manufacturing CA and the corresponding private key could exploit this vulnerability by presenting a valid certificate while attempting to connect to the targeted device. An exploit could allow the attacker to gain full control of all other components within the ACI fabric of an affected device.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2019-1590?

It affects 1 product.


Products: Cisco Nx-Os.

## How do I fix CVE-2019-1590?

No fix has been published for CVE-2019-1590 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1590 being exploited?

There is no known exploitation of CVE-2019-1590 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-2019-1590 and fix it if it is affected.

What it is: CVE-2019-1590 is a high-severity authentication bypass vulnerability in Cisco Nx-Os, 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-2019-1590 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-2019-1590/ (Markdown: https://insights.sbomify.com/CVE-2019-1590/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1590
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1590
- OSV: https://osv.dev/vulnerability/CVE-2019-1590

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-1590/
Summaries are generated and may contain mistakes; the official description above is the record.