# CVE-2011-0520: Memory corruption in n/a

> Remote attackers can cause a denial of service or execute arbitrary code via a heap-based buffer overflow in MaraDNS triggered by long DNS hostnames.

- **Severity:** High 7.5 (`AV:N/AC:L/Au:N/C:P/I:P/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:** 28 Jan 2011
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2011-0520, DSA-2196-1, GHSA-7vq7-qcwq-j3vc

## What is CVE-2011-0520?

CVE-2011-0520 is a high-severity memory corruption vulnerability in n/a, published on 28 Jan 2011. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The compress_add_dlabel_points function in dns/Compress.c in MaraDNS 1.4.03, 1.4.05, and probably other versions allows remote attackers to cause a denial of service (segmentation fault) and possibly execute arbitrary code via a long DNS hostname with a large number of labels, which triggers a heap-based buffer overflow.

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

## Which versions are affected by CVE-2011-0520?

It affects 1 product.


Products: Maradns Maradns.

## How do I fix CVE-2011-0520?

Apply the vendor's patch.

## Is CVE-2011-0520 being exploited?

There is no known exploitation of CVE-2011-0520 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2012-0024](https://insights.sbomify.com/CVE-2012-0024/): Denial of service in n/a (high 7.8)
- [CVE-2007-3115](https://insights.sbomify.com/CVE-2007-3115/): Denial of service in n/a (high 7.8)
- [CVE-2022-30256](https://insights.sbomify.com/CVE-2022-30256/): Other in n/a (high 7.5)
- [CVE-2011-5055](https://insights.sbomify.com/CVE-2011-5055/): Denial of service in n/a (medium 5.0)
- [CVE-2008-0061](https://insights.sbomify.com/CVE-2008-0061/): Denial of service in n/a (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2011-0520 and fix it if it is affected.

What it is: CVE-2011-0520 is a high-severity memory corruption vulnerability in n/a, published on 28 Jan 2011. 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-2011-0520 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-2011-0520/ (Markdown: https://insights.sbomify.com/CVE-2011-0520/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-0520
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-0520
- OSV: https://osv.dev/vulnerability/CVE-2011-0520

---
From sbomify Insights: https://insights.sbomify.com/CVE-2011-0520/
Summaries are generated and may contain mistakes; the official description above is the record.