# CVE-2024-20407: Security feature bypass in Cisco Firepower Threat Defense Software

> An unauthenticated remote attacker can bypass security policies on Cisco FTD devices using Snort 3 by exploiting a logic error in TCP Intercept handling.

- **Severity:** Medium 5.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Oct 2024
- **Updated:** 24 Oct 2024
- **Also known as:** GHSA-6vh9-9qf6-mvjj

## What is CVE-2024-20407?

CVE-2024-20407 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense, published on 23 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the interaction between the TCP Intercept feature and the Snort 3 detection engine on Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured policies on an affected system. Devices that are configured with Snort 2 are not affected by this vulnerability. 

 This vulnerability is due to a logic error when handling embryonic (half-open) TCP connections. An attacker could exploit this vulnerability by sending a crafted traffic pattern through an affected device. A successful exploit could allow unintended traffic to enter the network protected by the affected device.

Weakness: CWE-399

## Which versions are affected by CVE-2024-20407?

It affects 1 product.


Products: Cisco Secure Firewall Threat Defense.

## How do I fix CVE-2024-20407?

No fix has been published for CVE-2024-20407 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-20407 being exploited?

There is no known exploitation of CVE-2024-20407 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-2024-20407 and fix it if it is affected.

What it is: CVE-2024-20407 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense, published on 23 Oct 2024. 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-2024-20407 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-2024-20407/ (Markdown: https://insights.sbomify.com/CVE-2024-20407/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-20407
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-20407
- OSV: https://osv.dev/vulnerability/CVE-2024-20407

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-20407/
Summaries are generated and may contain mistakes; the official description above is the record.