# CVE-2022-20751: Cisco Firepower Threat Defense Software Snort Out of Memory Denial of Service Vulnerability

> Unauthenticated remote attackers can cause denial of service on Cisco Firepower Threat Defense devices by sending crafted IP packets that trigger excessive memory consumption.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/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:** 3 May 2022
- **Updated:** 6 Nov 2024
- **Also known as:** GHSA-6h2m-428h-qfcp

## What is CVE-2022-20751?

CVE-2022-20751 is a high-severity denial of service vulnerability in Cisco Secure Firewall Threat Defense, published on 3 May 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the Snort detection engine integration for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause unlimited memory consumption, which could lead to a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient memory management for certain Snort events. An attacker could exploit this vulnerability by sending a series of crafted IP packets that would generate specific Snort events on an affected device. A sustained attack could cause an out of memory condition on the affected device. A successful exploit could allow the attacker to interrupt all traffic flowing through the affected device. In some circumstances, the attacker may be able to cause the device to reload, resulting in a DoS condition.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2022-20751?

It affects 1 product.


Products: Cisco Secure Firewall Threat Defense.

## How do I fix CVE-2022-20751?

No fix has been published for CVE-2022-20751 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-20751 being exploited?

There is no known exploitation of CVE-2022-20751 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-2022-20751 and fix it if it is affected.

What it is: CVE-2022-20751 is a high-severity denial of service vulnerability in Cisco Secure Firewall Threat Defense, published on 3 May 2022. 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-2022-20751 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-2022-20751/ (Markdown: https://insights.sbomify.com/CVE-2022-20751/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-20751
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-20751
- OSV: https://osv.dev/vulnerability/CVE-2022-20751

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-20751/
Summaries are generated and may contain mistakes; the official description above is the record.