# CVE-2000-0549: Denial of service in n/a

> Remote attackers can cause a denial of service in Kerberos 4 KDC by sending malformed requests that lack null termination.

- **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:** 13 Oct 2000
- **Updated:** 8 Aug 2024
- **Also known as:** GHSA-5pwv-v67v-mf36

## What is CVE-2000-0549?

CVE-2000-0549 is a medium-severity denial of service vulnerability in Mit Kerberos 5, published on 13 Oct 2000. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Kerberos 4 KDC program does not properly check for null termination of AUTH_MSG_KDC_REQUEST requests, which allows remote attackers to cause a denial of service via a malformed request.

## Which versions are affected by CVE-2000-0549?

It affects 4 products.


Products: Cygnus Cygnus Network Security, Cygnus Kerbnet, Mit Kerberos, Mit Kerberos 5.

## How do I fix CVE-2000-0549?

No fix has been published for CVE-2000-0549 yet. Limit exposure of the affected software until one is available.

## Is CVE-2000-0549 being exploited?

There is no known exploitation of CVE-2000-0549 in the wild and no public exploit code.

## Other vulnerabilities in Mit Kerberos 5

- [CVE-2000-0389](https://insights.sbomify.com/CVE-2000-0389/): Memory corruption in n/a (critical 10.0)
- [CVE-2000-0390](https://insights.sbomify.com/CVE-2000-0390/): Memory corruption in n/a (critical 10.0)
- [CVE-2000-0391](https://insights.sbomify.com/CVE-2000-0391/): Memory corruption in n/a (critical 10.0)
- [CVE-2000-0392](https://insights.sbomify.com/CVE-2000-0392/): Memory corruption in n/a (high 7.2)
- [CVE-2000-0550](https://insights.sbomify.com/CVE-2000-0550/): Use after free in n/a (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2000-0549 and fix it if it is affected.

What it is: CVE-2000-0549 is a medium-severity denial of service vulnerability in Mit Kerberos 5, published on 13 Oct 2000. 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-2000-0549 in the wild and no public exploit code.

Affected product: Mit Kerberos 5. 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-2000-0549/ (Markdown: https://insights.sbomify.com/CVE-2000-0549/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2000-0549
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2000-0549
- OSV: https://osv.dev/vulnerability/CVE-2000-0549

---
From sbomify Insights: https://insights.sbomify.com/CVE-2000-0549/
Summaries are generated and may contain mistakes; the official description above is the record.