# CVE-2019-1727: Cisco NX-OS Software Python Parser Privilege Escalation Vulnerability

> Authenticated local attackers can escape the Python sandbox to execute arbitrary commands and elevate privileges on Cisco NX-OS devices.

- **Severity:** Medium 4.2 (`CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 May 2019
- **Updated:** 21 Nov 2024
- **Also known as:** GHSA-h9j3-p28g-73q9

## What is CVE-2019-1727?

CVE-2019-1727 is a medium-severity vulnerability in Cisco Nx-Os, published on 15 May 2019. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in the Python scripting subsystem of Cisco NX-OS Software could allow an authenticated, local attacker to escape the Python parser and issue arbitrary commands to elevate the attacker's privilege level. The vulnerability is due to insufficient sanitization of user-supplied parameters that are passed to certain Python functions in the scripting sandbox of the affected device. An attacker could exploit this vulnerability to escape the scripting sandbox and execute arbitrary commands to elevate the attacker's privilege level. To exploit this vulnerability, the attacker must have local access and be authenticated to the targeted device with administrative or Python execution privileges. These requirements could limit the possibility of a successful exploit.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-264

## Which versions are affected by CVE-2019-1727?

It affects 1 product.


Products: Cisco Nx-Os.

## How do I fix CVE-2019-1727?

No fix has been published for CVE-2019-1727 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1727 being exploited?

There is no known exploitation of CVE-2019-1727 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-2019-1727 and fix it if it is affected.

What it is: CVE-2019-1727 is a medium-severity vulnerability in Cisco Nx-Os, published on 15 May 2019. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-1727 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-2019-1727/ (Markdown: https://insights.sbomify.com/CVE-2019-1727/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1727
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1727
- OSV: https://osv.dev/vulnerability/CVE-2019-1727

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-1727/
Summaries are generated and may contain mistakes; the official description above is the record.