# CVE-2021-1539: Cisco ASR 5000 Series Software Authorization Bypass Vulnerabilities

> Authenticated remote attackers can bypass authorization to execute a subset of CLI commands on Cisco ASR 5000 devices.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Jun 2021
- **Updated:** 7 Nov 2024
- **Also known as:** GHSA-mmm7-3gcg-h332

## What is CVE-2021-1539?

CVE-2021-1539 is a high-severity missing authorization vulnerability in Cisco ASR 5000 Series Software, published on 4 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Multiple vulnerabilities in the authorization process of Cisco ASR 5000 Series Software (StarOS) could allow an authenticated, remote attacker to bypass authorization and execute a subset of CLI commands on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2021-1539?

It affects 2 products.


Products: Cisco Staros, Cisco Virtualized Packet Core.

## How do I fix CVE-2021-1539?

No fix has been published for CVE-2021-1539 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-1539 being exploited?

There is no known exploitation of CVE-2021-1539 in the wild and no public exploit code.

## Other vulnerabilities in Cisco ASR 5000 Series Software

- [CVE-2023-20046](https://insights.sbomify.com/CVE-2023-20046/): Auth bypass in Cisco ASR 5000 Series Software (high 8.8)
- [CVE-2019-1869](https://insights.sbomify.com/CVE-2019-1869/): Cisco StarOS Denial of Service Vulnerability (high 8.6)
- [CVE-2018-0369](https://insights.sbomify.com/CVE-2018-0369/): Denial of service in Cisco StarOS unknown (high 8.6)
- [CVE-2017-6707](https://insights.sbomify.com/CVE-2017-6707/): Command injection in Cisco StarOS (high 8.2)
- [CVE-2021-1540](https://insights.sbomify.com/CVE-2021-1540/): Cisco ASR 5000 Series Software Authorization Bypass Vulnerabilities (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1539 and fix it if it is affected.

What it is: CVE-2021-1539 is a high-severity missing authorization vulnerability in Cisco ASR 5000 Series Software, published on 4 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-1539 in the wild and no public exploit code.

Affected product: Cisco ASR 5000 Series Software. 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-2021-1539/ (Markdown: https://insights.sbomify.com/CVE-2021-1539/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1539
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1539
- OSV: https://osv.dev/vulnerability/CVE-2021-1539

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-1539/
Summaries are generated and may contain mistakes; the official description above is the record.