# CVE-2018-0090: Security feature bypass in Cisco NX-OS

> Unauthenticated attackers can bypass management interface ACLs on Cisco NX-OS switches, causing high CPU utilization and denial of service.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 18 Jan 2018
- **Updated:** 2 Dec 2024
- **Also known as:** GHSA-xww6-9qvq-r7pr

## What is CVE-2018-0090?

CVE-2018-0090 is a high-severity vulnerability in Cisco Nx-Os, published on 18 Jan 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in management interface access control list (ACL) configuration of Cisco NX-OS System Software could allow an unauthenticated, remote attacker to bypass configured ACLs on the management interface. This could allow traffic to be forwarded to the NX-OS CPU for processing, leading to high CPU utilization and a denial of service (DoS) condition. The vulnerability is due to a bad code fix in the 7.3.2 code train that could allow traffic to the management interface to be misclassified and not match the proper configured ACLs. An attacker could exploit this vulnerability by sending crafted traffic to the management interface. An exploit could allow the attacker to bypass the configured management interface ACLs and impact the CPU of the targeted device, resulting in a DoS condition. This vulnerability affects the following Cisco products running Cisco NX-OS System Software: Multilayer Director Switches, Nexus 2000 Series Switches, Nexus 3000 Series Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Switches in standalone NX-OS mode. Cisco Bug IDs: CSCvf31132.

Weakness: CWE-400 (Uncontrolled Resource Consumption), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-0090?

It affects 1 product.


Products: Cisco Nx-Os.

## How do I fix CVE-2018-0090?

No fix has been published for CVE-2018-0090 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-0090 being exploited?

There is no known exploitation of CVE-2018-0090 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-2018-0090 and fix it if it is affected.

What it is: CVE-2018-0090 is a high-severity vulnerability in Cisco Nx-Os, published on 18 Jan 2018. 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-2018-0090 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-2018-0090/ (Markdown: https://insights.sbomify.com/CVE-2018-0090/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0090
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0090
- OSV: https://osv.dev/vulnerability/CVE-2018-0090

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-0090/
Summaries are generated and may contain mistakes; the official description above is the record.