# CVE-2017-6633: Denial of service in Cisco UCS C-Series Rack Servers

> Remote attackers can cause denial of service on Cisco UCS C-Series servers by flooding TCP SYN packets due to insufficient rate limiting.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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:** 22 May 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-g9pg-mx97-6ghh

## What is CVE-2017-6633?

CVE-2017-6633 is a high-severity denial of service vulnerability in Cisco Unified Computing System, published on 22 May 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the TCP throttling process of Cisco UCS C-Series Rack Servers 3.0(0.234) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient rate-limiting protection. An attacker could exploit this vulnerability by sending a high rate of TCP SYN packets to a specific TCP listening port on an affected device. An exploit could allow the attacker to cause a specific TCP listening port to stop accepting new connections, resulting in a DoS condition. Cisco Bug IDs: CSCva65544.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2017-6633?

It affects 1 product.


Products: Cisco Unified Computing System.

## How do I fix CVE-2017-6633?

No fix has been published for CVE-2017-6633 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-6633 being exploited?

There is no known exploitation of CVE-2017-6633 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Unified Computing System

- [CVE-2026-20200](https://insights.sbomify.com/CVE-2026-20200/): Cisco Integrated Management Controller Argument Injection and Remote Code Execution Vulnerability (high 8.8)
- [CVE-2026-20094](https://insights.sbomify.com/CVE-2026-20094/): Cisco Integrated Management Controller Command Injection Vulnerability (high 8.8)
- [CVE-2018-0430](https://insights.sbomify.com/CVE-2018-0430/): Cisco Integrated Management Controller Command Injection Vulnerability (high 8.8)
- [CVE-2018-0431](https://insights.sbomify.com/CVE-2018-0431/): Cisco Integrated Management Controller Command Injection Vulnerability (high 8.8)
- [CVE-2012-4078](https://insights.sbomify.com/CVE-2012-4078/): Auth bypass in n/a (high 8.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-6633 and fix it if it is affected.

What it is: CVE-2017-6633 is a high-severity denial of service vulnerability in Cisco Unified Computing System, published on 22 May 2017. 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-2017-6633 in the wild and no public exploit code.

Affected product: Cisco Unified Computing System. 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-2017-6633/ (Markdown: https://insights.sbomify.com/CVE-2017-6633/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-6633
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-6633
- OSV: https://osv.dev/vulnerability/CVE-2017-6633

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-6633/
Summaries are generated and may contain mistakes; the official description above is the record.