# CVE-2006-4252: Denial of service in n/a

> Remote attackers can cause a denial of service in PowerDNS Recursor via a CNAME record with zero TTL, triggering an infinite loop.

- **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:** Yes
- **Published:** 14 Nov 2006
- **Updated:** 7 Aug 2024
- **Also known as:** DEBIAN-CVE-2006-4252, GHSA-mx38-c6fm-chc9

## What is CVE-2006-4252?

CVE-2006-4252 is a medium-severity denial of service vulnerability in Powerdns Recursor, published on 14 Nov 2006. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

PowerDNS Recursor 3.1.3 and earlier allows remote attackers to cause a denial of service (resource exhaustion and application crash) via a CNAME record with a zero TTL, which triggers an infinite loop.

## Which versions are affected by CVE-2006-4252?

It affects 1 product.


Products: Powerdns Recursor.

## How do I fix CVE-2006-4252?

Upgrade to a fixed version.

## Is CVE-2006-4252 being exploited?

There is no known exploitation of CVE-2006-4252 in the wild and no public exploit code.

## Other vulnerabilities in Powerdns Recursor

- [CVE-2009-4009](https://insights.sbomify.com/CVE-2009-4009/): Memory corruption in n/a (critical 10.0)
- [CVE-2020-10030](https://insights.sbomify.com/CVE-2020-10030/): Memory corruption in n/a (high 8.8)
- [CVE-2025-59023](https://insights.sbomify.com/CVE-2025-59023/): Crafted delegations or IP fragments can poison cached delegations in Recursor (high 8.2)
- [CVE-2025-59030](https://insights.sbomify.com/CVE-2025-59030/): Insufficient validation of incoming notifies over TCP can lead to a denial of service in Recursor (high 7.5)
- [CVE-2023-22617](https://insights.sbomify.com/CVE-2023-22617/): Denial of service in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2006-4252 and fix it if it is affected.

What it is: CVE-2006-4252 is a medium-severity denial of service vulnerability in Powerdns Recursor, published on 14 Nov 2006. 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-2006-4252 in the wild and no public exploit code.

Affected product: Powerdns Recursor. 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-2006-4252/ (Markdown: https://insights.sbomify.com/CVE-2006-4252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2006-4252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2006-4252
- OSV: https://osv.dev/vulnerability/CVE-2006-4252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2006-4252/
Summaries are generated and may contain mistakes; the official description above is the record.