# CVE-2004-0551: Denial of service in n/a

> Remote attackers can crash Cisco Catalyst switches by sending malformed TCP packets to Telnet, HTTP, or SSH services, causing a system reload.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jun 2004
- **Updated:** 8 Aug 2024
- **Also known as:** GHSA-cq5p-fgmw-rvxv

## What is CVE-2004-0551?

CVE-2004-0551 is a medium-severity denial of service vulnerability in n/a, published on 15 Jun 2004. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Cisco CatOS 5.x before 5.5(20) through 8.x before 8.2(2) and 8.3(2)GLX, as used in Catalyst switches, allows remote attackers to cause a denial of service (system crash and reload) by sending invalid packets instead of the final ACK portion of the three-way handshake to the (1) Telnet, (2) HTTP, or (3) SSH services, aka "TCP-ACK DoS attack."

## Which versions are affected by CVE-2004-0551?

It affects 24 products.


Products: Cisco Catalyst 2901, Cisco Catalyst 2902, Cisco Catalyst 2926, Cisco Catalyst 2926f, Cisco Catalyst 2926gl, Cisco Catalyst 2926gs, Cisco Catalyst 2926t, Cisco Catalyst 2948, Cisco Catalyst 2948-Ge-Tx, Cisco Catalyst 2948g-L3, Cisco Catalyst 2980g, Cisco Catalyst 2980g-A, Cisco Catalyst 4000, Cisco Catalyst 4500, Cisco Catalyst 4503, Cisco Catalyst 4506, Cisco Catalyst 4507r, Cisco Catalyst 4510r, Cisco Catalyst 4912g, Cisco Catalyst 5000 and 4 more.

## How do I fix CVE-2004-0551?

No fix has been published for CVE-2004-0551 yet. Limit exposure of the affected software until one is available.

## Is CVE-2004-0551 being exploited?

There is no known exploitation of CVE-2004-0551 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2004-0551 and fix it if it is affected.

What it is: CVE-2004-0551 is a medium-severity denial of service vulnerability in n/a, published on 15 Jun 2004. 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-2004-0551 in the wild and no public exploit code.

Affected product: n/a. 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-2004-0551/ (Markdown: https://insights.sbomify.com/CVE-2004-0551/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2004-0551
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2004-0551
- OSV: https://osv.dev/vulnerability/CVE-2004-0551

---
From sbomify Insights: https://insights.sbomify.com/CVE-2004-0551/
Summaries are generated and may contain mistakes; the official description above is the record.