# CVE-2018-15443: Cisco Firepower Detection Engine TCP Intrusion Prevention System Rule Bypass Vulnerability

> An unauthenticated remote attacker can bypass configured Intrusion Prevention System rules by sending crafted TCP traffic, allowing uninspected traffic onto the network.

- **Severity:** Medium 5.8 (`CVSS:3.0/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:** 8 Nov 2018
- **Updated:** 26 Nov 2024
- **Also known as:** GHSA-r3fv-hxw4-7fj4

## What is CVE-2018-15443?

CVE-2018-15443 is a medium-severity vulnerability in Cisco Firepower Management Center, published on 8 Nov 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a configured Intrusion Prevention System (IPS) rule that inspects certain types of TCP traffic. The vulnerability is due to incorrect TCP retransmission handling. An attacker could exploit this vulnerability by sending a crafted TCP connection request through an affected device. A successful exploit could allow the attacker to bypass configured IPS rules and allow uninspected traffic onto the network.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2018-15443?

It affects 1 product.


Products: Cisco Firepower System Software.

## How do I fix CVE-2018-15443?

No fix has been published for CVE-2018-15443 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-15443 being exploited?

There is no known exploitation of CVE-2018-15443 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Firepower Management Center

- [CVE-2018-0455](https://insights.sbomify.com/CVE-2018-0455/): Cisco Firepower System Software Detection Engine Denial of Service Vulnerability (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-15443 and fix it if it is affected.

What it is: CVE-2018-15443 is a medium-severity vulnerability in Cisco Firepower Management Center, published on 8 Nov 2018. 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-2018-15443 in the wild and no public exploit code.

Affected product: Cisco Firepower 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-2018-15443/ (Markdown: https://insights.sbomify.com/CVE-2018-15443/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-15443
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-15443
- OSV: https://osv.dev/vulnerability/CVE-2018-15443

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-15443/
Summaries are generated and may contain mistakes; the official description above is the record.