# CVE-2020-3549: Cisco Firepower Management Center Software and Firepower Threat Defense Software sftunnel Pass the Hash Vulnerability

> An attacker can intercept sftunnel traffic to obtain registration hashes, enabling decryption and modification of configuration and alert data between FMC and FTD devices.

- **Severity:** High 8.1 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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:** 21 Oct 2020
- **Updated:** 13 Nov 2024
- **Also known as:** GHSA-gcqw-x5jp-ph78

## What is CVE-2020-3549?

CVE-2020-3549 is a high-severity vulnerability in Cisco Secure Firewall Management Center, published on 21 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the sftunnel functionality of Cisco Firepower Management Center (FMC) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to obtain the device registration hash. The vulnerability is due to insufficient sftunnel negotiation protection during initial device registration. An attacker in a man-in-the-middle position could exploit this vulnerability by intercepting a specific flow of the sftunnel communication between an FMC device and an FTD device. A successful exploit could allow the attacker to decrypt and modify the sftunnel communication between FMC and FTD devices, allowing the attacker to modify configuration data sent from an FMC device to an FTD device or alert data sent from an FTD device to an FMC device.

Weakness: CWE-326 (Inadequate Encryption Strength)

## Which versions are affected by CVE-2020-3549?

It affects 2 products.


Products: Cisco Secure Firewall Management Center, Cisco Secure Firewall Threat Defense.

## How do I fix CVE-2020-3549?

No fix has been published for CVE-2020-3549 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3549 being exploited?

There is no known exploitation of CVE-2020-3549 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Secure Firewall Management Center

- [CVE-2026-20079](https://insights.sbomify.com/CVE-2026-20079/): Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel (critical 10.0, exploited in the wild)
- [CVE-2026-20131](https://insights.sbomify.com/CVE-2026-20131/): Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data (critical 10.0, exploited in the wild)
- [CVE-2026-20316](https://insights.sbomify.com/CVE-2026-20316/): Cisco Secure Firewall Management Center Use of Hard-coded Password (medium 5.3, exploited in the wild)
- [CVE-2025-20265](https://insights.sbomify.com/CVE-2025-20265/): Cisco Secure Firewall Management Center Software Radius Remote Code Execution Vulnerability (critical 10.0)
- [CVE-2024-20424](https://insights.sbomify.com/CVE-2024-20424/): Command injection in Cisco Firepower Management Center (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3549 and fix it if it is affected.

What it is: CVE-2020-3549 is a high-severity vulnerability in Cisco Secure Firewall Management Center, published on 21 Oct 2020. 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-2020-3549 in the wild and no public exploit code.

Affected product: Cisco Secure Firewall Management Center. 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-2020-3549/ (Markdown: https://insights.sbomify.com/CVE-2020-3549/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3549
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3549
- OSV: https://osv.dev/vulnerability/CVE-2020-3549

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3549/
Summaries are generated and may contain mistakes; the official description above is the record.