# CVE-2015-0721: Auth bypass in n/a

> Remote authenticated users can bypass AAA restrictions to gain privileged CLI access on Cisco NX-OS devices via crafted SSH parameters.

- **Severity:** High 8.0 (`CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 6 Oct 2016
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-68pv-f96f-2qwf

## What is CVE-2015-0721?

CVE-2015-0721 is a high-severity authentication bypass vulnerability in Cisco Nx-Os, published on 6 Oct 2016. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Cisco NX-OS 4.0 through 7.3 on Multilayer Director and Nexus 1000V, 2000, 3000, 3500, 4000, 5000, 5500, 5600, 6000, 7000, 7700, and 9000 devices allows remote authenticated users to bypass intended AAA restrictions and obtain privileged CLI access via crafted parameters in an SSH connection negotiation, aka Bug IDs CSCum35502, CSCuw78669, CSCuw79754, and CSCux88492.

Weakness: CWE-264

## Which versions are affected by CVE-2015-0721?

It affects 1 product.


Products: Cisco Nx-Os.

## How do I fix CVE-2015-0721?

No fix has been published for CVE-2015-0721 yet. Limit exposure of the affected software until one is available.

## Is CVE-2015-0721 being exploited?

There is no known exploitation of CVE-2015-0721 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-2015-0721 and fix it if it is affected.

What it is: CVE-2015-0721 is a high-severity authentication bypass vulnerability in Cisco Nx-Os, published on 6 Oct 2016. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2015-0721 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-2015-0721/ (Markdown: https://insights.sbomify.com/CVE-2015-0721/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-0721
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-0721
- OSV: https://osv.dev/vulnerability/CVE-2015-0721

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-0721/
Summaries are generated and may contain mistakes; the official description above is the record.