# CVE-2020-3253: Cisco Firepower Threat Defense Software Shell Access Vulnerability

> An authenticated local attacker can bypass expert mode restrictions to gain root shell access on Cisco Firepower Threat Defense devices.

- **Severity:** Medium 6.7 (`CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 6 May 2020
- **Updated:** 15 Nov 2024
- **Also known as:** GHSA-v33g-rjxr-6hm4

## What is CVE-2020-3253?

CVE-2020-3253 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense, published on 6 May 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in the support tunnel feature of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to access the shell of an affected device even though expert mode is disabled. The vulnerability is due to improper configuration of the support tunnel feature. An attacker could exploit this vulnerability by enabling the support tunnel, setting a key, and deriving the tunnel password. A successful exploit could allow the attacker to run any system command with root access on an affected device.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2020-3253?

It affects 1 product.


Products: Cisco Secure Firewall Threat Defense.

## How do I fix CVE-2020-3253?

No fix has been published for CVE-2020-3253 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3253 being exploited?

There is no known exploitation of CVE-2020-3253 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Secure Firewall Threat Defense

- [CVE-2024-20412](https://insights.sbomify.com/CVE-2024-20412/): Hardcoded credentials in Cisco Firepower Threat Defense Software (critical 9.3)
- [CVE-2024-20330](https://insights.sbomify.com/CVE-2024-20330/): Memory corruption in Cisco Firepower Threat Defense Software (high 8.6)
- [CVE-2024-20339](https://insights.sbomify.com/CVE-2024-20339/): Cisco Firepower Threat Defense Software for Firepower 2100 Series TLS Denial of Service Vulnerability (high 8.6)
- [CVE-2024-20351](https://insights.sbomify.com/CVE-2024-20351/): Cisco Firepower Threat Defense Software Snort Firewall Denial of Service Vulnerability (high 8.6)
- [CVE-2023-20083](https://insights.sbomify.com/CVE-2023-20083/): Denial of service in Cisco Firepower Threat Defense Software (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3253 and fix it if it is affected.

What it is: CVE-2020-3253 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense, published on 6 May 2020. 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-2020-3253 in the wild and no public exploit code.

Affected product: Cisco Secure Firewall Threat Defense. 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-2020-3253/ (Markdown: https://insights.sbomify.com/CVE-2020-3253/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3253
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3253
- OSV: https://osv.dev/vulnerability/CVE-2020-3253

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-3253/
Summaries are generated and may contain mistakes; the official description above is the record.